[Federal Register: April 8, 2005 (Volume 70, Number 67)]
[Rules and Regulations]
[Page 18135-18191]
From the Federal Register Online via GPO Access [wais.access.gpo.gov]
[DOCID:fr08ap05-8]
[[Page 18135]]
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Part III
Department of Transportation
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National Highway and Traffic Safety Administration
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49 CFR Parts 571 and 585
Federal Motor Vehicle Safety Standards; Tire Pressure Monitoring
Systems; Controls and Displays; Final Rule
[[Page 18136]]
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DEPARTMENT OF TRANSPORTATION
National Highway Traffic Safety Administration
49 CFR Parts 571 and 585
[Docket No. NHTSA 2005-20586]
RIN 2127-AJ23
Federal Motor Vehicle Safety Standards; Tire Pressure Monitoring
Systems; Controls and Displays
AGENCY: National Highway Traffic Safety Administration (NHTSA), DOT.
ACTION: Final rule.
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SUMMARY: This final rule establishes a new Federal motor vehicle safety
standard (FMVSS) requiring installation of a tire pressure monitoring
system (TPMS) capable of detecting when one or more of a vehicle's
tires is significantly under-inflated. This final rule responds to a
mandate in the Transportation Recall Enhancement, Accountability, and
Documentation (TREAD) Act. This final rule requires installation in all
new light vehicles of a TPMS capable of detecting when one or more of
the vehicle's tires, up to all four tires, is 25 percent or more below
the manufacturer's recommended inflation pressure (placard pressure) or
a minimum activation pressure specified in the standard, whichever is
higher.
DATES: Effective Date: This final rule is effective April 8, 2005,
except for subpart G of 49 CFR part 585, which is effective September
1, 2005.
Compliance Date: Consistent with the phase-in commencing October 5,
2005, all new light vehicles must be equipped with a TPMS that meets
the requirements of the standard by September 1, 2007, with the
following exceptions. Vehicle manufacturers need not meet the
standard's requirements for the TPMS malfunction indicator and related
owner's manual language until September 1, 2007 (i.e., at the end of
the phase-in), and vehicles produced by final-stage manufacturers and
alterers must be equipped with a compliant TPMS (including a
malfunction indicator) by September 1, 2008. However, manufacturers may
voluntarily certify vehicles to FMVSS No. 138 and earn carry-forward
credits for compliant vehicles, produced in excess of the phase-in
requirements, that are manufactured between April 8, 2005, and the
conclusion of the phase-in.
Petitions for Reconsideration: If you wish to submit a petition for
reconsideration of this rule, your petition must be received by May 23,
2005.
ADDRESSES: Petitions for reconsideration should refer to the docket
number above and be submitted to: Administrator, Room 5220, National
Highway Traffic Safety Administration, 400 Seventh Street, SW.,
Washington, DC 20590.
See the SUPPLEMENTARY INFORMATION portion of this document (Section
VIII; Rulemaking Analyses and Notice) for DOT's Privacy Act Statement
regarding documents submitted to the agency's dockets.
FOR FURTHER INFORMATION CONTACT: For non-legal issues, you may call Mr.
George Soodoo or Mr. Samuel Daniel, Office of Crash Avoidance Standards
(Telephone: 202-366-2720) (Fax: 202-366-4329).
For legal issues, you may call Mr. Eric Stas, Office of the Chief
Counsel (Telephone: 202-366-2992) (Fax: 202-366-3820).
You may send mail to these officials at National Highway Traffic
Safety Administration, 400 Seventh Street, SW., Washington, DC 20590.
SUPPLEMENTARY INFORMATION:
Table of Contents
I. Executive Summary
A. Requirements of the Final Rule
B. Lead Time and Phase-In
C. Differences Between the Final Rule and the Notice of Proposed
Rulemaking
D. Impacts of the Final Rule
II. Background
A. The TREAD Act
B. Rulemaking History Prior to the September 2004 Notice of
Proposed Rulemaking
III. September 2004 Notice of Proposed Rulemaking (NPRM) and Public
Comments
A. The NPRM
B. Summary of Public Comments on the NPRM
IV. The Final Rule and Response to Public Comments
A. Summary of the Requirements
B. Lead Time and Phase-In
C. Response to Public Comments by Issue
1. Low Tire Pressure Warning Lamp Activation Requirement
(a) Under-Inflation Detection Level
(b) Time Period for Low Pressure Detection
2. TPMS Malfunction Indicator Lamp (MIL) Activation Requirements
(a) Time Period for Malfunction Detection
(b) What Constitutes a TPMS Malfunction?
(c) MIL Disablement
3. Telltale Requirements
(a) Function and Format of the Combined Low Pressure Warning/
Malfunction Indicator Lamp
(b) Telltale Symbols for Low Pressure Warning and Malfunction
Indication
(c) Telltale Color
(i) Low Pressure Warning Telltale
(ii) Malfunction Indicator Telltale
(d) Telltale Extinguishment Requirements
(e) Telltale Illumination Priority
(f) Supplemental Telltale
4. Tire-Related Issues
(a) Replacement Tires and Spare Tires
(b) Tire Reserve Load
(c) Changes to Tire Publications
(d) Minimum Activation Pressure
5. Owner's Manual Requirements
6. Test Procedures
(a) Calibration Time
(b) Driving Conditions
(c) MIL Activation
(d) Vehicle Cool-Down Period
(e) Testing with Pressures Other Than Placard Pressure
(f) System Reset
7. Lead Time and Phase-In
(a) Lead Time
(b) Phase-In Schedule
8. Small Business Impacts
9. Environmental Impacts
10. Maintenance Issues
(a) TPMS Maintenance
(b) Tire Maintenance
11. Markings for Vehicles with Direct TPMSs
12. Definitions
(a) ``Tires''
(b) ``Manual Reset''
13. Educational Efforts
14. Alternative Systems
15. Over-Inflation Detection
16. Temperature and Altitude Compensation
17. System Longevity
18. Harmonization
V. Benefits
VI. Costs
VII. Regulatory Alternatives
VIII. Rulemaking Analyses and Notices
I. Executive Summary
This final rule re-establishes FMVSS No. 138, Tire Pressure
Monitoring Systems, which requires installation of a tire pressure
monitoring system in light vehicles, thereby implementing a mandate in
the TREAD Act. In accord with the Act, the objective of this standard
is to supplement regular tire maintenance on the part of drivers by
providing a warning system to alert them when one or more of a
vehicle's tires become significantly under-inflated. Under-inflation of
tires increases the likelihood of many different types of crashes,
including those involving: (1) Skidding and/or
[[Page 18137]]
loss of control of the vehicle; (2) hydroplaning; (3) increases in
stopping distance; (4) flat tires and blowouts, and (5) overloading of
the vehicle. We anticipate that 90 percent of drivers will respond to a
TPMS low tire pressure warning by re-inflating their tires to the
recommended placard pressure. Once all new light vehicles are equipped
with compliant TPMSs, we expect that a resulting 119-121 fatalities
would be prevented each year.
As background, we note that Standard No. 138 was promulgated
previously through a final rule published in the Federal Register on
June 5, 2002 (67 FR 38704). It included two compliance options (i.e., a
TPMS with a four-tire, 25-percent under-inflation detection capability
or a TPMS with a one-tire, 30-percent under-inflation detection
capability). However, on August 6, 2003, the U.S. Court of Appeals for
the Second Circuit (Second Circuit) issued its opinion in Public
Citizen v. Mineta,\1\ which held that the TREAD Act requires a TPMS
capable of detecting when any combination of tires, up to all four
tires, is significantly under-inflated. It vacated FMVSS No. 138 and
directed the agency to conduct further rulemaking. This final rule sets
requirements for the TPMS standard in a manner consistent with the
Second Circuit's opinion. It also responds to numerous public comments
submitted in response to the agency's September 16, 2004 notice of
proposed rulemaking (NPRM) (69 FR 55896).
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\1\ 340 F.3d 39 (2d Cir. 2003).
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A. Requirements of the Final Rule
After careful consideration of all available information, including
public comments, the agency has decided to retain in the final rule
most of the elements of the proposed rule, with the primary changes
involving the detection times for providing the low tire pressure
warning and TPMS malfunction warning, modification of the minimum
activation pressure values for certain light truck tires, and
modifications to the standard's phase-in schedule. Although public
comments on the NPRM discussed a wide variety of issues, the majority
of comments focused on the topics of the TPMS malfunction indicator and
the proposed schedule for lead time and phase-in, the two major aspects
of the NPRM not raised at earlier stages of the TPMS rulemaking.
As reflected in the final rule, FMVSS No. 138 is a performance
standard. The agency has sought to establish the standard in a fashion
that both meets the need for motor vehicle safety and is also
technology-neutral. Particularly in light of the rapid advances in TPMS
technology in the past few years, we expect that vehicle manufacturers
will have a number of technologies available for compliance purposes.
Although the details of the standard, public comments, and the agency's
response thereto, are discussed at length in the balance of this
document, the following points summarize the key requirements of the
standard.
Consistent with the Second Circuit's opinion, FMVSS No. 138
requires new passenger cars, multi-purpose passenger vehicles, trucks,
and buses with a gross vehicle weight rating (GVWR) of 4,536 kg (10,000
pounds) or less, except those with dual wheels on an axle, to be
equipped with a TPMS to alert the driver when one or more of the
vehicle's tires, up to a total of all four tires, is significantly
under-inflated. Specifically, the TPMS must warn the driver when the
pressure in one or more of the vehicle's tires is 25 percent or more
below the vehicle manufacturer's recommended cold inflation pressure,
or a minimum level of pressure specified in the standard, whichever
pressure is higher. (We note that in response to a petition for
rulemaking by the Alliance of Automobile Manufacturers (Alliance) and
that organization's subsequent, related comments on the NPRM, we have
decided, as an interim measure, to modify our minimum activation
pressure (MAP) values for some light truck tires under the standard.
Once the agency conducts further safety research, we will either
confirm or propose to modify these MAP requirements in response to that
petition.)
If any tire drops below the standard's activation threshold, the
TPMS is required to provide the low tire pressure warning by
illuminating a yellow telltale within 20 minutes of additional travel
within a speed range of 50-100 km/hr. This telltale must remain
illuminated (and re-illuminate upon subsequent vehicle start-ups) until
the under-inflation condition has been corrected. The agency has
determined that the specified under-inflation threshold and the
detection time will allow the TPMS to provide a timely warning that
permits the driver to take corrective action before adverse
consequences ensue. Thus, we believe that the low inflation pressure
detection requirement of the standard both fulfills the mandate of the
TREAD Act and meets the need for motor vehicle safety.
Because a small number of aftermarket and replacement tires have
construction characteristics that may prevent the continued proper
functioning of the TPMS when the original equipment tires are replaced
and because of the difficulty in identifying those problematic tires,
NHTSA has decided to require the vehicle to be certified with the tires
originally installed on the vehicle at the time of initial vehicle
sale. (This reflects a change from the June 2002 final rule, which
required vehicle manufacturer to certify continued compliance with any
optional or replacement tires of the size(s) recommended by the vehicle
manufacturer.)
Nevertheless, we expect that a typical vehicle will outlast its
original set of tires, and we continue to believe that it is important
that drivers continue to receive the benefits of the TPMS after the
vehicle's tires are replaced. Therefore, we have decided upon a
different approach than that contained in the June 2002 final rule for
addressing the issue of maintaining proper TPMS functionality when a
vehicle's original tires are replaced. Specifically, the final rule
requires the TPMS to include a malfunction indicator (provided either
by a separate telltale or a combined low tire pressure/malfunction
indicator telltale) that would alert the driver in situations in which
the TPMS is unable to detect low tire pressure.
This malfunction indicator is required to detect incompatible
replacement tires, as well as other system faults. Similar to the low
tire pressure warning, the system is required to trigger a TPMS
malfunction warning telltale within 20 minutes of additional travel
within a speed range of 50-100 km/hr after such a malfunction occurs.
Consistent with the specific requirements of the standard, this
telltale must remain illuminated (and re-illuminate upon subsequent
vehicle start-ups) until the TPMS malfunction has been corrected. We
believe that the TPMS malfunction indicator will provide useful
information to the driver regarding the long-term operability of the
TPMS, thereby increasing the overall benefits of the system.
The final rule also specifies required language to be included in
the vehicle owner's manual (or in writing to the first purchaser if
there is no owner's manual) that describes the purpose of the low tire
pressure warning telltale, the consequences of significantly under-
inflated tires, the meaning of the low tire pressure telltale when it
is illuminated, and corrective action to be taken. The owner's manual
must also explain the presence and operation of the TPMS malfunction
indicator and the potential problems associated with aftermarket and
replacement tires and
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rims that may prevent continued TPMS functionality. These provisions
are designed to ensure that consumers are aware of the importance of
regular tire maintenance and of the supporting role played by their
vehicle's TPMS.
The final rule provides that compliance testing for FMVSS No. 138
will be conducted on a specific test course, namely the Southern Loop
of the Treadwear Course in and around San Angelo, Texas. We believe
that this approach offers several advantages. First, testing can be
conducted in a timely fashion without the need to design or build a new
test track. Further, this course has already been used for several
years by NHTSA and the tire industry for uniform tire quality grading
(UTQG) purposes. We believe that the specified test course provides an
objective test that is representative of a variety of roadways and real
world conditions.
B. Lead Time and Phase-In
In order to provide the public with the safety benefits of TPMSs as
rapidly as possible, compliance with this final rule is set to commence
on October 5, 2005, which marks the start of a two-part phase-in
period. Subject to the special provisions discussed below, the phase-in
schedule for FMVSS No. 138 is as follows: 20 percent of a vehicle
manufacturer's light vehicles are required to comply with the standard
during the period from October 5, 2005, to August 31, 2006; 70 percent
during the period from September 1, 2006 to August 31, 2007, and all
light vehicles thereafter.
For the reasons discussed in detail in section IV.B of this notice,
we believe that it is practicable for vehicle manufacturers to meet the
requirements of the phase-in discussed above, with the following
exceptions. We have decided to defer vehicle manufacturers' compliance
with the standard's malfunction indicator requirements and associated
owner's manual language requirements until September 1, 2007. (There is
no separate phase-in for the malfunction indicator requirements.) After
consideration of the many public comments from vehicle manufacturers on
this issue, we understand that adding the TPMS malfunction indicator
will involve substantial design and production changes and that
additional lead time will be required to effect those changes. In
addition, our analysis demonstrates that the safety benefits associated
with the early introduction of TPMSs, even without malfunction
indicators, far outweigh the benefits of delaying the standard until
all systems also can meet the malfunction indicator requirements. We
note that manufacturers may voluntarily install a TPMS malfunction
indicator prior to the mandatory compliance date.
Because our statute generally requires that a standard may not
compel compliance less than 180 days after the standard is
prescribed,\2\ we have decided to postpone the starting compliance date
from the NPRM's proposed date of September 1, 2005 to a date that
corresponding to 180 days after publication of this final rule.
However, we have decided to have the balance of the standard's phase-in
coincide with traditional model year production schedules, in order to
mitigate production and cost impacts.
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\2\ 49 U.S.C. 30111(d).
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We have decided not to delay the start of compliance until Model
Year 2007, as several commenters suggested. If the agency were to
forego the first year of the phase-in, we would expect to lose 24 lives
and to have 1,675 more injuries than would have occurred if TPMSs had
been provided in vehicles, as called for in the final rule's phase-in.
Moreover, vehicle manufacturers have been well aware of the key
requirements of the final rule (other then the malfunction indicator
requirement), at least since the time of the Second Circuit's decision
in August 2003 (if not earlier), and the September 2004 NPRM clearly
conveyed the agency's intention to begin a phase-in that would coincide
with Model Year (MY) 2006. Further, they did not provide any data to
demonstrate that compliance with a Fall 2005 start of the phase-in
would be impracticable. In addition, we believe that concerns related
to lead time are either rendered moot or significantly mitigated by the
final rule's allowance of both carry-forward and carry-backward
credits.
As a means of maintaining a mandatory compliance date in Fall 2005,
we have decided to ease implementation further by permitting carry-
forward and carry-back credits. Vehicle manufacturers can earn carry-
forward credits for compliant vehicles, produced in excess of the
phase-in requirements, that are manufactured between the effective date
of this rule and the conclusion of the phase-in.\3\ In order to
maximize the time available to earn such credits, we are making this
final rule effective upon publication, although vehicle manufacturers
have no certification responsibilities until the official start of the
phase-in.
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\3\ We note that carry-forward credits may not be used to defer
the mandatory compliance date of September 1, 2007 for all covered
vehicles.
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With carry-backward credits, manufacturers may defer compliance
with a part or all of the certification requirements under the standard
for the first period of the phase-in, provided they certify a
correspondingly increased number of vehicles during the second period
of the phase-in. We believe that permitting carry-backward credits
would not impact the overall safety benefits of the final rule because
the same number of vehicles would be subject to compliance
certification, although the distribution may vary over the model years
of the phase-in.
On other topics related to the phase-in, NHTSA has decided to
exclude multi-stage manufacturers and alterers from the requirements of
the phase-in and to extend by one year the time for compliance by those
manufacturers (i.e., until September 1, 2008). The final rule also
excludes small volume manufacturers (i.e., manufacturers producing less
than 5,000 vehicles for sale in the U.S. market in one year) from the
phase-in, requiring vehicles produced by such manufacturers to comply
with the standard on September 1, 2007.
C. Differences Between the Final Rule and the Notice of Proposed
Rulemaking
As noted above, NHTSA has decided to adopt most of the provisions
contained in the NPRM as part of this final rule. The main differences
between the NPRM and the final rule involve the phase-in schedule for
the standard, the requirements for low tire pressure and TPMS
malfunction detection time, changes to the minimum activation pressure
for certain light truck tires, and modifications to the vehicle owner's
manual requirements. A number of minor technical modifications also
were incorporated in the final rule in response to public comments on
the NPRM. All of these changes and their rationale are discussed fully
in the balance of this document. However, the following points briefly
describe the main differences between the NPRM and this final rule.
In the final rule, we have decided to increase the time
period for the TPMS to detect low tire pressure to 20 minutes. The NPRM
had proposed a time period of 10 minutes for the TPMS to detect low
tire pressure and illuminate the warning telltale.
The final rule specifies a time period for the TPMS to
detect a system malfunction and to illuminate the TPMS malfunction
indicator (20 minutes) and acknowledged that many systems may require
vehicle motion to detect a malfunction. The NPRM had been silent on
these matters.
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The agency has decided to require the words (`` TPMS'')
for the dedicated TPMS malfunction telltale, rather than the symbol
proposed in the NPRM. We have also lengthened the time period for
flashing of the combined low tire pressure/malfunction indicator
telltale from the proposed one minute to a period of 60-90 seconds.
The final rule has adopted minimum activation pressures
for light truck Load Range ``D'' and ``E'' tires of 35 psi (240 kPa),
which is different from the values in the NPRM. (However, the agency
has stated that it is conducting further research in this area and that
it may revisit this issue.)
The final rule's requirements for the specified statement
in the owner's manual regarding the TPMS have changed from the NPRM.
Specifically, these changes include clarification that both aftermarket
tires and rims may affect the TPMS's continued functionality, tailoring
of the language to reflect the two options for the TPMS malfunction
indicator, stressing of the driver's ongoing responsibility for regular
tire maintenance, and alerting consumers that some replacement tires
may call for an inflation pressure different than what is reflected on
the vehicle placard.
In the final rule's test procedures, we have deleted the
NPRM's test requirements related to system reset. We have decided that
this provision is impracticable, based upon how most resets operate,
and unnecessary, because vehicles equipped with a TPMS reset normally
include instructions for the proper use of the reset feature as part of
the owner's manual.
The final rule's phase-in schedule has changed from the NPRM's 50-
90-100% requirement to a 20-70-100% requirement. In another change from
the NPRM, vehicle manufacturers are not required to meet the standard's
requirements for the TPMS malfunction indicator (and associated owner's
manual requirements) until the end of the phase-in (i.e., September 1,
2007).
The final rule permits vehicle manufacturers to elect to
use carry-backward credits in meeting the phase-in requirements under
the standard. That provision was not present in the NPRM.
The final rule extends the compliance date for final-stage
manufacturers and alterers by one year (i.e., to September 1, 2008).
The NPRM had proposed to require compliance for these manufacturers'
production by September 1, 2007.
D. Impacts of the Final Rule
Depending upon the technology chosen for compliance, the agency
estimates that the total quantified safety benefits from reductions in
crashes due to skidding/loss of control, stopping distance, flat tires,
and blowouts, will be 119-121 fatalities prevented and 8,373-8,568
injuries prevented or reduced in severity each year, once all light
vehicles meet the TPMS requirement.
Additional benefits are expected to accrue from the final rule as a
result of improved fuel economy ($19.07-$23.08 per vehicle over its
lifetime), longer tread life ($3.42-$4.24 per vehicle), and property
damage savings and travel delay savings from avoided crashes ($7.70-
$7.79 per vehicle) (assuming a three-percent discount rate).
The agency estimates that the average cost per vehicle to meet the
standard's requirements to be $48.44-$69.89, depending upon the
technology chosen for compliance. Since approximately 17 million light
vehicles are produced for sale in the U.S. each year, the total annual
vehicle cost is expected to range from approximately $823-$1,188
million per year.
II. Background
A. The TREAD Act
Congress enacted the TREAD Act \4\ on November 1, 2000. Section 13
of that Act \5\ required the Secretary of Transportation, within one
year of the statute's enactment, to complete a rulemaking ``to require
a warning system in new motor vehicles to indicate to the operator when
a tire is significantly under inflated.'' Section 13 also required the
regulation to take effect within two years of the completion of the
rulemaking. Responsibility for this rulemaking was delegated to NHTSA.
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\4\ Pub. L. 106-414, 114 Stat. 1800 (2000).
\5\ See 49 U.S.C. 30123 note (2003).
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B. Rulemaking History Prior to the September 2004 Notice of Proposed
Rulemaking
FMVSS No. 138, Tire Pressure Monitoring Systems, has had a
protracted regulatory history. The following discussion briefly
summarizes the key milestones in the TPMS rulemaking process.
Today's final rule was preceded by an initial NPRM on July 26, 2001
(66 FR 38982). After considering public comments received on that NPRM,
NHTSA prepared a final rule, which was submitted to the Office of
Management and Budget (OMB) for review. After reviewing the draft final
rule, OMB returned it to NHTSA for further consideration, with a letter
explaining the reasons for doing so, on February 12, 2002.
On June 5, 2002, NHTSA published a final rule for TPMS (67 FR
38704). Consistent with the OMB return letter, the agency divided the
TPMS final rule into two parts, because it decided to defer its
decision as to which long-term performance requirements for TPMS would
best satisfy the mandate of the TREAD Act. This deferral was intended
to allow the agency time to consider additional data on the effect and
performance of TPMSs currently in use.
The June 5, 2002 final rule provided two compliance options during
the interim period (i.e., between November 1, 2003 and October 31,
2006). Under the first compliance option, vehicle manufacturers would
have been required to equip their light vehicles (i.e., those with a
GVWR of 4,536 kg (10,000 pounds) or less) with TPMSs to warn the driver
when the pressure in any single tire or in each tire in any combination
of tires, up to a total of four tires, is 25 percent or more below the
vehicle manufacturer's recommended cold inflation pressure for the
tires, or a minimum level of pressure specified in the standard,
whichever pressure is higher. Under the second compliance option, the
vehicle's TPMS would have been required to warn the driver when the
pressure in any single tire is 30 percent or more below the vehicle
manufacturer's recommended cold inflation pressure for the tires, or a
minimum level of pressure specified in the standard, whichever pressure
is higher.\6\
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\6\ The minimum levels of pressure were the same for both
compliance options.
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The two compliance options were outgrowths of the alternative sets
of requirements proposed in the initial NPRM. In response to comments
indicating that current indirect TPMSs could not meet the NPRM's
proposed detection requirements, the agency adopted a one-tire, 30-
percent option that would have permitted indirect TPMSs to be used
during the phase-in period.\7\ NHTSA received 13 petitions
[[Page 18140]]
for reconsideration of the June 2002 final rule, raising a variety of
issues.
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\7\ There are two types of TPMSs currently available, direct
TPMSs and indirect TPMSs. Direct TPMSs have a pressure sensor in
each wheel that transmits pressure information to a receiver. In
contrast, indirect TPMSs do not have tire pressure sensors, but
instead rely on the wheel speed sensors, typically a component of an
anti-lock braking system, to detect and compare differences in the
rotational speed of a vehicle's wheels, which correlate to
differences in tire pressure.
We anticipate that new types of TPMS technology may be developed
in the future that will be capable of meeting the standard's
requirements. For example, such systems might incorporate aspects of
both direct and indirect TPMSs (i.e., hybrid systems). In concert
with TPMS suppliers, tire manufacturers might be able to incorporate
TPMS sensors directly into the tires themselves. In issuing a
performance standard, NHTSA is cognizant of and seeks to encourage
technological innovation.
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However, after issuance of the June 2002 final rule, Public
Citizen, Inc., New York Public Interest Research Group, and the Center
for Auto Safety filed a suit challenging certain aspects of the TPMS
regulation. The Court of Appeals for the Second Circuit issued its
opinion in Public Citizen, Inc. v. Mineta on August 6, 2003, which held
that the agency's adoption in the standard of a one-tire, 30-percent
compliance option was ``contrary to the intent of the TREAD Act and, in
light of the relative shortcomings of indirect systems, arbitrary and
capricious.'' \8\ The Court found that the TREAD Act unambiguously
mandates TPMSs capable of monitoring each tire, up to a total of four
tires, effectively precluding the one-tire, 30-percent option, or any
similar option that cannot detect under-inflation in any combination of
tires up to four tires.
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\8\ 340 F.3d 39, 54 (2d Cir. 2003).
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Ultimately, the Court vacated the standard (FMVSS No. 138) in its
entirety and directed the agency to issue a new rule consistent with
its August 6, 2003 opinion. NHTSA published a final rule in the Federal
Register on November 20, 2003, vacating FMVSS No. 138 (68 FR 65404).
With the standard vacated, that notice clarified that, at that point in
time, vehicle manufacturers had no certification or reporting
responsibilities.
In light of the foregoing, NHTSA commenced rulemaking efforts to
reestablish FMVSS No. 138 in a manner consistent with the Court's
opinion and responsive to the issues raised in earlier petitions for
reconsideration, the majority of which remained relevant. To this end,
the agency issued a second NPRM on September 16, 2004 (69 FR 55896)
(discussed immediately below) and obtained and considered public
comments on that NPRM, actions leading to this latest final rule for
TPMS.
For a more complete discussion of this earlier period of the
regulatory history of the TPMS rulemaking, readers should consult the
June 5, 2002 final rule and the September 16, 2004 NPRM.
III. September 2004 Notice of Proposed Rulemaking (NPRM) and Public
Comments
A. The NPRM
As noted above, NHTSA published an NPRM on September 16, 2004 that
proposed to re-establish FMVSS No. 138, Tire Pressure Monitoring
Systems, in a manner consistent with the Court's opinion. Specifically,
it proposed to require passenger cars, multipurpose passenger vehicles,
trucks, and buses with a GVWR of 4,536 kg (10,000 pounds) or less,
except those with dual wheels on an axle, to be equipped with a TPMS to
alert the driver when one or more of the vehicle's tires, up to all
four of its tires, are significantly under-inflated. The NPRM was
drafted so as to be technology-neutral, so as to permit compliance with
any available TPMS technology that meets the performance requirements.
The NPRM included the following points, which highlighted the key
provisions of the proposed requirements.
The TPMS would be required to warn the driver when the
pressure in one or more of the vehicle's tires, up to a total of four
tires, is 25 percent or more below the vehicle manufacturer's
recommended cold inflation pressure for the tires, or a minimum level
of pressure specified in the standard, whichever pressure is higher.
Vehicle manufacturers would be required to certify vehicle
compliance under the standard with the tires installed on the vehicle
at the time of initial vehicle sale.\9\
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\9\ The NPRM noted that some vehicle manufacturers authorize
their dealers to replace the vehicle's factory-installed tires with
other tires, including ones with a different size and/or recommended
cold tire inflation pressure. The NPRM stated that the TPMS would
have to perform properly with any such tires, because the vehicle
could be equipped with those tires at the time of initial sale. Of
course, the manufacturer would not have that responsibility if the
dealer installed other tires without manufacturer authorization.
However, the dealer would violate the Motor Vehicle Safety Act if it
installed tires on a new vehicle that prevented the TPMS from
functioning properly. See 49 U.S.C. 30112(a).
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The TPMS would be required to include a low pressure
telltale (yellow) that must remain illuminated as long as any of the
vehicle's tires remains under-inflated and the vehicle's ignition
locking system is in the ``On'' (``Run'') position. The telltale would
be required to extinguish when all of the vehicle's tires cease to be
significantly under-inflated. The TPMS's low tire pressure warning
telltale would be required to perform a bulb-check at vehicle start-up.
The TPMS also would be required to include a malfunction
indicator to alert the driver when the system is non-operational and,
thus, unable to provide the required low tire pressure warning. The
NPRM proposed that TPMS malfunction could be indicated by either:
(1) Installing a separate, dedicated telltale (yellow) that
illuminates upon detection of the malfunction and remains continuously
illuminated as long as the ignition locking system is in the ``On''
(``Run'') position and the situation causing the malfunction remains
uncorrected, or
(2) Designing the low tire pressure telltale so that it flashes for
one minute when a malfunction is detected, after which the telltale
would remain illuminated as long as the ignition locking system is in
the ``On'' (''Run'') position. This flashing and illumination sequence
would be repeated upon each subsequent vehicle start-up until the
situation causing the malfunction has been corrected.
If the option for a separate telltale is selected, the TPMS
malfunction telltale would be required to perform a bulb-check at
vehicle start-up.
The TPMS would not be required to monitor the spare tire
(if provided) either when it is stowed or when it is installed on the
vehicle.
For vehicles certified under the standard, vehicle
manufacturers would be required to provide in the owner's manual an
explanation of the purpose of the low tire pressure warning telltale,
the potential consequences of significantly under-inflated tires, the
meaning of the telltale when it is illuminated, and what actions
drivers should take when the telltale is illuminated. Vehicle
manufacturers also would be required to provide a specified statement
in the owner's manual regarding: (1) Potential problems related to
compatibility between the vehicle's TPMS and various replacement tires,
and (2) the presence and operation of the TPMS malfunction indicator.
The NPRM proposed requirements for covered vehicles manufactured on
or after September 1, 2005 (i.e., MY 2006), subject to the following
phase-in schedule: 50 percent of a vehicle manufacturer's light
vehicles would be required to comply with the standard during the first
year (September 1, 2005 to August 31, 2006); 90 percent during the
second year (September 1, 2006 to August 31, 2007); and all vehicles
thereafter.
The NPRM stated that in order to encourage early compliance, the
agency was proposing to permit carry-forward credits for vehicles that
are certified as complying with the standard and that are manufactured
on or after the
[[Page 18141]]
effective date of the final rule. However, under the proposal,
beginning September 1, 2007, all covered vehicles would be required to
comply with the standard, without regard to any earlier carry-forward
credits.
We proposed to exclude from the phase-in requirements final stage
manufacturers, alterers, and small volume manufacturers (SVMs). The
NPRM also proposed phase-in reporting requirements consistent with the
proposed phase-in schedule.
B. Summary of Public Comments on the NPRM
NHTSA received comments on the September 16, 2004 NPRM from a
variety of interested parties including 10 TPMS manufacturers,\10\ 13
automobile manufacturers and their trade associations,\11\ seven tire
manufacturers and their trade associations,\12\ two public interest
groups,\13\ and six other interested organizations.\14\ Comments were
also received from 24 individuals. All of these comments may be found
in Docket No. NHTSA-2004-19054.
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\10\ Comments were received from the following TPMS
manufacturers: (1) ALPS Automotive, Inc.; (2) Aviation Upgrade
Technologies; (3) BERU Corporation; (4) Continental Teves, Inc.; (5)
Emtop Ltd.; (6) EnTire Solutions, LLC; (7) ETV Corporation Pty
Limited; (8) MLHO, Inc.; (9) NIRA Dynamics AB, and (10) Schrader
Electronics Ltd.
\11\ Comments were received from the following automobile
manufacturers and related trade associations: (1) Alliance of
Automobile Manufacturers; (2) American Suzuki Motor Corporation; (3)
Association of International Automobile Manufacturers, Inc.; (4) BMW
of North America, LLC; (5) DaimlerChrysler Corporation; (6)
DaimlerChrysler and Mercedes-Benz U.S.A.; (7) Fuji Heavy Industries
USA, Inc. (makers of Subaru vehicles); (8) General Motors North
America; (9) Honda Motor Co., Ltd. and American Honda Motor Co.,
Inc.; (10) Hyundai American Technical Center, Inc./Kia Motors
Corporation; (11) Mitsubishi Motors R&D of America, Inc.; (12)
Nissan North America, Inc.; (13) Porsche Cars North America, Inc.,
and (14) Volkswagen/Audi.
\12\ Comments were received from the following tire
manufacturers and related trade associations: (1) European Tyre and
Rim Technical Organisation; (2) Japan Automobile Tyre Manufacturers
Association, Inc.; (3) Rubber Manufacturers Association; (4)
Sumitomo Rubber Industries; (5) The Tire Rack; (6) Tire and Rim
Association, Inc., and (7) Tire Industry Association.
\13\ Comments were received from the following public interest
groups: (1) Advocates for Highway and Auto Safety, and (2) Public
Citizen.
\14\ Comments were received from the following other interested
manufacturers, trade associations, and groups: (1) American
Automobile Association; (2) the European Communities; (3) Fairfax
County Public Schools; (4) GE Infrastructure Sensing; (5) National
Automobile Dealers Association, and (6) Specialty Equipment Market
Association.
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The commenters raised a variety of issues with the proposed
requirements, including ones related to the low tire pressure warning
lamp activation, the TPMS malfunction indicator lamp, the TPMS low
pressure and MIL telltales, test procedures, minimum activation
pressure requirements, the need for a tire reserve load, owner's manual
requirements, TPMS operation with replacement tires/spare tires, lead
time and phase-in, and other topics. The following discussion
summarizes the main issues raised by these public comments and the
positions expressed on these topics. A more complete discussion of the
public comments is provided under Section IV.C, which provides an
explanation of the agency rationale for the requirements of the final
rule and addresses related public comments by issue.
Low Tire Pressure Warning Lamp Activation Requirements
Regarding the activation requirements for the low tire pressure
warning lamp, commenters raised concerns related to the NPRM's proposed
under-inflation detection level, as well as the proposed 10-minute time
period for under-inflation detection. Public interest groups and
certain other commenters urged NHTSA to adopt a more stringent
threshold for under-inflation detection (ranging from 15-20 percent
below placard pressure). These commenters argued that existing
technologies (i.e., direct TPMSs) can detect and warn the driver at
lesser levels of under-inflation, thereby permitting drivers more time
to take corrective action and maximizing the benefits provided by the
system.
The tire industry also urged NHTSA to adopt a more stringent under-
inflation detection threshold, with a trigger point tied to the vehicle
placard pressure and the Gross Axle Weight Rating (GAWR). Specifically,
the comment of TIA stated that the under-inflation detection warning
should be triggered at 1-2 psi below the vehicle's recommended cold
tire inflation pressure or at an inflation level where the tires can no
longer carry the vehicle weight, whichever is higher. Other commenters
suggested that the under-inflation detection threshold should take into
account various vehicle loading conditions.
Vehicle manufacturers did not comment on the under-inflation
detection level, which suggests that they do not object to that aspect
of the NPRM.
Regarding the NPRM's proposed 10-minute time period for low tire
pressure detection, vehicle manufacturers generally recommended
extending that time period, arguing that even direct systems would
require additional time to detect, confirm, and relay a warning about a
significantly under-inflated tire. Comments from vehicle manufacturers
also suggested that in order to be technology-neutral and to permit
vehicle certification with indirect systems, the under-inflation
detection time should be extended in situations where the vehicle has
two, three, or four significantly under-inflated tires; those comments
argued that there is not a safety need for rapid detection in such
cases, where under-inflation is likely to result from diffusion over a
considerable period of time.
Public interest groups, the European Communities (EC), and certain
other industry commenters argued that the proposed 10-minute detection
time period is too long and that it would allow vehicles to continue to
travel in a potentially unsafe condition without a warning. These
comments suggested that such situations are unnecessary because
technology currently exists that would permit a shorter detection time.
TPMS MIL Activation Requirements
Regarding the time period for malfunction detection, vehicle
manufacturers stated their concern regarding the absence in the NPRM of
an expressed time period for the TPMS to detect a malfunction and to
illuminate the TPMS MIL. Commenters stated that immediate detection, as
implied by the NPRM, is not technically possible and that in most
cases, the vehicle must be driven in order to detect a malfunction.
Several commenters stated that TPMSs cannot detect malfunctions any
faster than the system can detect low tire pressure (because the same
subsystems are involved) and that the same durational parameters should
be set for both functions (with suggestions ranging from 20-30
minutes).
A number of manufacturers commented that the proposed TPMS
malfunction requirements are overly broad and are in need of
modification. Specific commenters asserted that TPMSs would have
difficulties detecting or reporting various types of malfunctions.
One commenter raised the issue of MIL disablement (or suppression)
in situations where the TPMS sending units have been removed as a
result of the replacement of the original equipment tires and rims with
aftermarket components that are not compatible with the direct-sensing
TPMS. (The NPRM made no provision for MIL disablement.)
Telltale Requirements
A number of commenters discussed the issue of how the TPMS MIL
would operate, particularly when it is combined with the low tire
pressure warning telltale. Some commenters,
[[Page 18142]]
primarily representing vehicle manufacturers, argued that the MIL
requirements are design-restrictive and may impose unnecessary costs.
Those commenters requested flexibility in providing the malfunction
warning through a variety of means (e.g., text messaging and audible
warnings), provided that the warning is explained in the vehicle
owner's manual.
Several commenters expressed concern about how the malfunction
warning would be provided to the driver in a combined telltale. Some
commenters argued that flashing should be used to indicate low tire
pressure; some argued that flashing should be used to indicate
malfunction; some argued that the flashing sequence should be longer,
and still others argued that any sort of flashing may be confusing to
drivers.
Public interest groups generally favored requiring a separate
telltale to indicate TPMS malfunction, in order to provide a clear
message to drivers. However, manufacturers commented that separate
telltales are unnecessary, add cost, and consume valuable space on the
instrument panel that could be used to provide other safety messages.
Commenters overwhelmingly recommended that NHTSA reconsider its
proposed symbol to indicate a TPMS malfunction, which was considered to
be confusing, and a variety of alternatives were suggested. Some
commenters expressed support for only permitting a low tire pressure
telltale that indicates which tire is under-inflated, because such
symbol is both more recognizable and offers enhanced information to the
driver.
Regarding telltale color, some manufacturers recommended permitting
the low tire pressure telltale to change color (e.g., from yellow to
red) to indicate when under-inflation has progressed to a dangerously
low level, as determined by the vehicle manufacturer. Commenters also
raised the issue of the color of the TPMS MIL, with some recommending
yellow and others recommending red.
In their comments, manufacturers also raised issues related to
extinguishment of the TPMS telltales. For example, concerns were raised
regarding the possibility of a TPMS reset button extinguishing the
telltale before the underlying problem (i.e., low tire pressure or
system malfunction) has been corrected. Others suggested that the final
rule should specify that tires must be re-inflated to a level at least
10 percent above the warning threshold before the TPMS low pressure
telltale would extinguish.
Another topic raised by commenters related to the TPMS combined
telltale involved requests for the final rule to set an illumination
priority for the low tire pressure and TPMS malfunction warnings.
Commenters did not agree as to which warning should take precedence.
Tire-Related Issues
Another major area of comment involved tire issues. Regarding the
issue of the NPRM's proposed approach for TPMS operation with
replacement and spare tires, public interest groups generally objected
to the agency's tentative decision to require compliance certification
with the tires originally installed on the vehicle, but to require a
malfunction indicator to indicate to the driver when replacement tires
have been installed on the vehicle which prevent the continued proper
functioning of the TPMS. Those commenters suggested that the TPMS
should either be required to function with all replacement tires and
original equipment (OE) full-sized spare tires (so as to provide
continuing operational benefits to consumers) or that there should be
ongoing efforts to make the public aware of those tires which have been
found to prevent proper TPMS functioning.
Comments from the tire industry also supported a requirement for
the TPMS to operate with replacement tires, particularly in light of
those tires' prevalence in the marketplace. Those commenters further
argued that vehicle manufacturers should be required to provide
affordable access to TPMS service information to all tire dealers and
service providers. Other commenters expressed concern regarding the
impact the proposed rule would have on small businesses.
The tire industry recommended that the final rule should include a
tire pressure reserve requirement in order to ensure that the vehicle
can safely carry the vehicle maximum load, even if the tires are under-
inflated by 25 percent below placard pressure. Otherwise, commenters
argued that the vehicle's tires may fall below the level designated in
the tire industry's load/pressure tables but still not trigger a low
pressure warning from the TPMS. These commenters were especially
concerned that this situation could lead to increased instances of tire
failure, particularly if drivers come to rely on the TPMS as a
substitute for regular tire maintenance. Moreover, the Tire and Rim
Association (TRA) stated its intention to modify its 2005 Year Book to
provide additional instruction for manufacturers of TPMS-equipped
vehicles.
The Alliance commented that the NPRM's proposed Table 1, which
specifies minimum activation pressures for different tires, should be
modified for Load Range ``C,'' ``D,'' and ``E'' light truck (LT) tires.
According to the Alliance, the MAPs currently contained in Table 1 do
not allow such tires to be used across the safe operating ranges of
inflation pressures for which loads are specified in the TRA Yearbooks.
The Alliance argued that unless corrective action is taken, vehicle
manufacturers could face costly vehicle redesigns or be forced to
substitute less capable tires in certain vehicle applications.
Owner's Manual Requirements
Several commenters suggested modifications to the NPRM's proposed
language related to TPMSs for the vehicle owner's manual. One comment
involved allowing vehicle manufacturers discretion to tailor the
owner's manual statement to the system installed on the vehicle,
provided that certain basic topics were addressed. Other comments
included clarifying the discussion of permissible telltale formats, of
proper pressures for replacement wheel/tire combinations, and of
ongoing driver responsibility for maintaining proper tire inflation
pressure.
Test Procedures
Commenters raised a number of issues related to the NPRM's proposed
test conditions and procedures. The issue of calibration time was
raised, with at least one manufacturer commenter suggesting that no
calibration period is necessary, and other manufacturer commenters
arguing that the NPRM's proposed 20-minute calibration time should be
extended to 30 minutes or one hour.
Comments from the tire industry recommended that the test
conditions and performance parameters in the final rule should be
expanded to capture a fuller range of real world driving conditions.
Specifically, these comments recommended expanding the proposed ambient
temperature range to include colder and warmer temperatures, testing
under slippery road conditions, and expanding the vehicle speed range
to include both slower and faster speeds.
Commenters also offered suggestions pertaining to the test
procedures for TPMS MIL activation, which would implement their
recommendations regarding the types of malfunctions the system should
be required to detect and how quickly they should be detected.
[[Page 18143]]
Manufacturers also commented on the proposed cool-down period of up
to one hour, as contained in S6(e) of the proposed test procedures. The
Alliance recommended reducing the cool-down period to five minutes or
less, arguing that in certain cases, tires deflated during testing when
cold may warm up to a point above the warning threshold before the TPMS
has time to detect a significantly under-inflated tire. Other
commenters made similar arguments and recommended adding additional
pressure checks to the test procedures to ensure that the pressure
level has been set accurately during testing.
Other commenters urged NHTSA to modify the test procedures to
recognize that testing may need to be conducted with a pressure other
than placard pressure in order to properly match the load on the tires.
These comments suggested that the owner's manual should be consulted in
order to select the proper pressure under certain situations.
Several commenters also raised issues regarding use of a system
reset feature during testing, including use in situations where the
driver switches between summer and winter tires.
Lead Time and Phase-In
In general, most of the vehicle manufacturers that commented on the
NPRM requested additional lead time and a modified phase-in schedule,
arguing that more time is necessary to incorporate TPMS technologies
into their new vehicle production processes. Most vehicle manufacturer
commenters recommended a two-year phase-in, with an initial compliance
date beginning on September 1, 2006. Furthermore, vehicle manufacturers
universally commented that it would not be possible to incorporate the
TPMS MIL until September 1, 2007.
In contrast, public interest groups expressed support for the
NPRM's compliance schedule, as proposed.
Other Issues
Commenters also raised a variety of other issues in response to the
NPRM. These included small business impacts, environmental impacts,
maintenance issues, markings on vehicles equipped with direct TPMSs,
definitions, educational efforts, alternative systems, over-inflation
detection, temperature and altitude compensation, system longevity, and
harmonization. Comments on each of these issues will be described and
addressed in section IV.C of this notice.
IV. The Final Rule and Response to Public Comments
A. Summary of the Requirements
After careful consideration of public comments on the NPRM, this
final rule re-establishes FMVSS No. 138, Tire Pressure Monitoring
Systems, in a manner consistent with the Second Circuit's opinion.
Specifically, it requires passenger cars, multi-purpose passenger
vehicles, trucks, and buses with a GVWR of 4,536 kg (10,000 pounds) or
less, except those with dual wheels on an axle, to be equipped with a
TPMS to alert the driver when one or more of the vehicle's tires, up to
all four of its tires, is significantly under-inflated. Subject to the
phase-in schedule and the exceptions below, compliance with the
requirements of the final rule commences for covered vehicles
manufactured on or after October 5, 2005 (i.e., MY 2006). The standard
is intended to be technology-neutral, so as to permit compliance with
any available TPMS technology that meets the standard's performance
requirements.
The following points highlight the key provisions of the final
rule.
The TPMS is required to detect and to provide a warning to
the driver within 20 minutes of when the pressure of one or more of the
vehicle's tires, up to a total of four tires, is 25 percent or more
below the vehicle manufacturer's recommended cold inflation pressure
for the tires, or a minimum level of pressure specified in the
standard, whichever pressure is higher. These minimum activation
pressures are included in Table 1 of FMVSS No. 138.\15\
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\15\ We note that the Alliance of Automobile Manufacturers
submitted a Petition for Rulemaking on April 29, 2003 that asks
NHTSA to make certain changes to the MAPs in Table 1 (see Docket No.
NHTSA-2000-8572-265). For a more complete discussion of the MAP
issue raised by the Alliance, see section IV.C.4.d of this document.
NHTSA is in the process of evaluating the issues raised in the
Alliance petition. However, we have decided to modify the values in
Table 1 pertaining to Load Range ``D'' and ``E'' tires, pending
completion of our analysis.
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Vehicle manufacturers must certify vehicle compliance
under the standard with the tires installed on the vehicle at the time
of initial vehicle sale.\16\
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\16\ We note that some vehicle manufacturers authorize their
dealers to replace the vehicle's factory-installed tires with other
tires, including ones with a different size and/or recommended cold
tire inflation pressure. The TPMS must perform properly with any
such tires, because the vehicle could be equipped with those tires
at the time of initial sale. Of course, the manufacturer would not
have that responsibility if the dealer installed other tires without
manufacturer authorization.
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The TPMS must include a low tire pressure warning telltale
\17\ (yellow) that must remain illuminated as long as any of the
vehicle's tires remain significantly under-inflated and the vehicle's
ignition locking system is in the ``On'' (``Run'') position.\18\ The
TPMS's low tire pressure warning telltale must perform a bulb-check at
vehicle start-up.
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\17\ As part of this final rule, we are adding two versions of
the TPMS low tire pressure telltale and a TPMS malfunction telltale
to Table 2 of FMVSS No. 101, Controls and Displays. The regulatory
text in this final rule incorporates the TPMS telltales in Table 2,
as that table currently exists in the Code of Federal Regulations.
However, we note that NHTSA published an NPRM in the Federal
Register on September 23, 2003 that proposes to update and to expand
FMVSS No. 101 (68 FR 55217). Publication of the present version of
Table 2 here is not intended to suggest a change in approach to the
ongoing FMVSS No. 101 rulemaking. We anticipate incorporating the
TPMS telltales in a revised Table 2, once a final decision is
reached on updating Standard No. 101.
\18\ We note that if a vehicle manufacturer elects to install a
low tire pressure telltale that indicates which tire is under-
inflated, the telltale must correctly identify the under-inflated
tire. See S4.3.2.
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The TPMS must also include a TPMS malfunction indicator to
alert the driver when the system is non-operational, and thus unable to
provide the required low tire pressure warning.\19\ The TPMS
malfunction indicator must detect a malfunction within 20 minutes of
occurrence and provide a warning to the driver. This final rule
provides two options by which vehicle manufacturers may indicate a TPMS
malfunction:
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\19\ We note that the TPMS telltale(s) may be incorporated as
part of a reconfigurable display, provided all requirements of the
standard are met.
---------------------------------------------------------------------------
(1) Installation of a separate, dedicated telltale (yellow) that
illuminates upon detection of the malfunction and remains continuously
illuminated as long as the ignition locking system is in the ``On''
(``Run'') position and the situation causing the malfunction remains
uncorrected, or
(2) Designing the low tire pressure telltale so that it flashes for
a period of at least 60 seconds and no longer than 90 seconds when a
malfunction is detected, after which the telltale must remain
continuously illuminated as long as the ignition locking system is in
the ``On'' (``Run'') position. This flashing and illumination sequence
must be repeated upon each subsequent vehicle start-up until the
situation causing the malfunction has been corrected.
If the option for a separate telltale is selected, the TPMS
malfunction telltale must perform a bulb-check at vehicle start-up.
The TPMS is not required to monitor the spare tire (if
provided),
[[Page 18144]]
either when it is stowed or when it is installed on the vehicle.
For vehicles certified under the standard, vehicle
manufacturers must provide in the owner's manual a specified statement
explaining the purpose of the low tire pressure warning telltale, the
potential consequences of significantly under-inflated tires, the
meaning of the telltale when it is illuminated, and what actions
drivers should take when the telltale is illuminated. Vehicle
manufacturers also must provide a specified statement in the owner's
manual regarding: (1) potential problems related to compatibility
between the vehicle's TPMS and various replacement or alternate tires
and wheels, and (2) the presence and operation of the TPMS malfunction
indicator. For vehicles that do not come with an owner's manual, the
required information must be provided in writing to the first purchaser
at the time of initial vehicle sale.
B. Lead Time and Phase-In
As discussed in the NPRM, the Second Circuit's decision vacating
FMVSS No. 138 necessitated a change in the standard's phase-in schedule
in order to ensure the practicability of the standard's implementation,
particularly for those manufacturers that had intended to certify to
the June 5, 2002 final rule's one-tire, 30-percent option. Responses to
the agency's September 9, 2003 Special Orders to 14 vehicle
manufacturer and 13 TPMS suppliers demonstrated that in anticipation of
the start of the phase-in under the June 2002 final rule, most vehicle
manufacturers were moving aggressively toward installation of TPMSs
capable of meeting the four-tire, 25-percent detection requirement,
although some were not. The information provided by TPMS suppliers
indicated sufficient capacity to supply TPMSs with a four-tire, 25-
percent detection capability in quantities that would easily meet the
phase-in requirements. Accordingly, in the NPRM, the agency proposed
that 50 percent of a vehicle manufacturer's light vehicles would be
required to comply with the standard during the first year (September
1, 2005 to August 31, 2006); 90 percent during the second year
(September 1, 2006 to August 31, 2007); and all vehicles thereafter.
In public comments on the NPRM, vehicle manufacturers argued that
they would not be able to meet the standard's requirements given the
proposed lead time and phase-in schedule. Most of their concerns
involved the TPMS malfunction indicator, a newly proposed requirements
which manufacturers uniformly agreed would necessitate significant
engineering and vehicle design efforts and corresponding production
changes. Vehicle manufacturers stated that they could meet the TPMS MIL
requirements (and associated owner's manual requirements) by September
1, 2007. More generally, vehicle manufacturers commented that, setting
aside the issue of the MIL requirements, the phase-in schedule
nevertheless may be too aggressive.
We acknowledge that the TPMS MIL represents a new requirement
impacting TPMS design and functionality and that vehicle manufacturers
may require additional time to incorporate the MIL into their
production processes. However, we do not believe that implementation of
the entire standard should be delayed until technical changes related
to the TPMS MIL can be fully resolved, because that would deny the
public the safety benefits of TPMSs in the meantime. Accordingly, we
believe that it is preferable to move rapidly to implement the
standard, but to delay the compliance date only for the TPMS MIL
requirements and associated requirements in the owner's manual.
In light of the above and subject to the vehicle manufacturer
option for carry-backward credits discussed below, NHTSA has decided to
adopt the following phase-in schedule: 20 percent of a vehicle
manufacturer's light vehicles are required to comply with the standard
during the period from October 5, 2005, to August 31, 2006; 70 percent
during the period from September 1, 2006 to August 31, 2007, and all
light vehicles thereafter. However, vehicle manufacturers are not
required to comply with the requirements related to the TPMS
malfunction indicator (including associated owner's manual
requirements) until September 1, 2007; however, at that point, all
covered vehicles must meet all relevant requirements of the standard
(i.e., no additional phase-in for MIL requirements). The final rule
includes phase-in reporting requirements consistent with the phase-in
schedule discussed above.
Small volume manufacturers (i.e., those manufacturers producing
fewer than 5,000 vehicles for sale in the U.S. per year during the
phase-in period) are not subject to the phase-in requirements, but
their vehicles must meet the requirements of the standard beginning
September 1, 2007.
Consistent with the policy set forth in NHTSA's February 14, 2005
final rule on certification requirements for vehicles built in two or
more stages and altered vehicles (70 FR 7414), final-stage
manufacturers and alterers must certify compliance for covered vehicles
manufactured on or after September 1, 2008. However, final-stage
manufacturers and alterers may voluntarily certify compliance with the
standard prior to this date.
NHTSA has decided to permit vehicle manufacturers to earn carry-
forward credits for compliant vehicles, produced in excess of the
phase-in requirements, that are manufactured between the effective date
of this rule and the conclusion of the phase-in. These carry-forward
credits could be used during the phase-in, but they could not be used
to delay compliance certification for vehicles produced after the
conclusion of the phase-in. Except for vehicles produced by final-stage
manufacturers and alterers (who receive an additional year for
compliance), all covered vehicles must comply with FMVSS No. 138 on
September 1, 2007, without use of any carry-forward credits.
Furthermore, we have determined that there is good cause to make
this final rule effective upon publication so that vehicle
manufacturers would have a standard in effect to which they may certify
vehicles for purposes of early, voluntary compliance and to maximize
the time for earning carry-forward credits. We explicitly note that
vehicle manufacturers have no mandatory compliance responsibilities
under the standard until the start of the phase-in.
To further ease implementation, we have decided to also provide
carry-backward credits, whereby vehicle manufacturers may defer
compliance with a part or all of the certification requirements for the
first period of the phase-in, provided that they certify a
correspondingly larger percentage of vehicles under the standard during
the second period of the phase-in. We believe that permitting carry-
backward credits would not impact the overall safety benefits of the
final rule, because the same number of vehicles would be subject to
compliance certification, although the distribution may vary over the
model years of the phase-in. Corresponding changes have been added to
the regulatory text of both FMVSS No. 138, as well as the TPMS phase-in
requirements contained in 49 CFR Part 585.
C. Response to Public Comments by Issue
As noted previously, public comments on the September 2004 NPRM for
TPMS raised a variety of issues with the NPRM's proposed requirements.
Each of these topics will be discussed in turn, in order to explain
[[Page 18145]]
how these comments impacted the agency's determinations in terms of
setting requirements for this final rule.
1. Low Tire Pressure Warning Lamp Activation Requirement
(a) Under-Inflation Detection Level. The NPRM proposed to require
the TPMS to illuminate a low tire pressure warning telltale not more
than 10 minutes after the inflation pressure in one or more of the
vehicle's tires, up to a total of four tires, is equal to or less than
the pressure 25 percent below the vehicle manufacturer's recommended
cold inflation pressure or the pressure specified in the 3rd column of
Table 1 of this standard for the corresponding tire type, whichever is
higher (see S4.2(a)).
A number of commenters raised concerns about the 25-percent under-
inflation detection level proposed in the NPRM. Although their
reasoning differed, these commenters all argued that a more stringent
detection level should be required under the final rule.
Public Citizen stated that a 20-percent threshold should be
adopted. Public Citizen argued that NHTSA's technology-neutral
standard, as proposed, was crafted to accommodate indirect TPMSs (which
Public Citizen considers to be an ``inferior technology'') when there
is other adequate technology readily available (i.e., direct TPMSs).
(Advocates for Highway and Auto Safety (Advocates) provided a similar
comment.) According to Public Citizen, NHTSA should not reduce safety
requirements in order to accommodate inferior technology, particularly
when other affordable and more effective technology exists.
Public Citizen stated that the aspect of the agency's rationale
that a higher threshold could discourage technological innovation is
unsubstantiated. The comments of Public Citizen similarly characterized
as unsubstantiated NHTSA's concerns about nuisance warnings that could
result from a detection level that is set too close to placard pressure
and requested substantive driver behavioral research to confirm that
this would be a problem. (Similarly, Advocates argued that NHTSA acted
arbitrarily in selecting a 25-percent under-inflation threshold (as
opposed to the 20-percent level proposed in the 2001 NPRM) and that the
record does not justify NHTSA's claim that a 20-percent under-inflation
detection level would result in nuisance warnings.)
Public Citizen rounded out its comments in this area by
characterizing the NPRM's 25-percent under-inflation detection level as
a cost-saving measure. It argued that safety should outweigh cost
considerations and that NHTSA's other rulemaking activities provided
support for adopting a 20-percent under-inflation detection level
(e.g., the 2001 TPMS NPRM and the agency's rollover research). The
Advocates argued that NHTSA has not compared the actual benefits of the
two thresholds and suggested that NHTSA's New Car Assessment Program
(NCAP) data would support the theory that different pressure levels
correlate with different levels of risk.
Fairfax County Public Schools expressed support for a system that
either provides a built-in tire pressure gauge or provides an earlier
warning, such as a 20-percent under-inflation detection level. It
stated that it is not always easy to find a functioning air compressor
when traveling, so it is better to provide an earlier indication before
the vehicle is past the point of safe operation.
Mr. James Anderson, an individual, commented that the under-
inflation detection level should be set at some point between 15
percent and 18 percent below placard pressure, the point at which the
commenter argued that the tire sidewall begins to over-flex. According
to Mr. Anderson, as the tire over-flexes, heat begins to build up, but
the tire is no longer able to dissipate the heat. Mr. Anderson stated
that at some point above 200 [deg]F, the tire compounds begin a
reversion process, which may lead to delamination and, ultimately,
separation of tire components. He argued that a warning level 25-
percent below placard pressure would not permit sufficient time for
driver recognition and timely action to correct the under-inflation
situation before tire damage may occur.
The Tire Industry Association (TIA) argued that the proposed TPMS
under-inflation detection level is too lenient, suggesting that the
trigger point instead should be tied to the vehicle's placard pressure
and GAWR. Specifically, TIA stated that the under-inflation detection
warning should be triggered at 1-2 psi below the vehicle's recommended
cold tire inflation pressure or at an inflation level where the tires
can no longer carry the vehicle weight, whichever is higher. (TIA's
argument here is related to the issue of Tire Reserve Load, a topic
discussed later in this document.) TIA argued that the standard should
require the TPMS to provide a warning before there is a serious
problem, thereby taking into account that drivers may not immediately
take corrective action when the warning telltale illuminates.
ETV Corporation (ETV) stated that the TPMS should be required to
take into account different load conditions in determining the need to
activate the low tire pressure warning.
The National Automobile Dealers Association (NADA) stated that
although the final rule must factor in technological and cost
constraints, it should specify the smallest under-inflation threshold
that can be reliably monitored.
EnTire Solutions, LLC (EnTire) commented that the direct TPMSs it
produces are capable of providing low pressure warnings at a more
stringent threshold than the NPRM's proposed 25-percent under-inflation
detection level. EnTire also stated that its system and those of other
TPMS manufacturers have multiple thresholds for under-inflation
detection. GE Infrastructure Sensing stated that technology currently
exists for TPMSs to detect a 20-percent under-inflation level.
The Tire Rack argued that the 25-percent under-inflation detection
level does not provide an adequate and timely warning to the driver and
may provide a false sense of security. The Tire Rack also stated that,
to the extent the 25-percent under-inflation detection level reflects
limitations of current technology, the final rule should establish
successively more stringent requirements in order to ensure future
improvements in TPMS technology. It argued that establishing goals and
timetables as part of the final rule would encourage technological
developments for TPMSs.
The American Automobile Association (AAA) stated that the NPRM
proposes to set the under-inflation warning threshold at a level that
is insufficiently stringent, because a tire that is 25 percent below
the manufacturer's recommended inflation pressure could already present
a dangerous situation, particularly if the vehicle is in a fully-loaded
condition. AAA argued that under-inflated tires ``produce increased
heat, which is a major cause of failure.'' According to AAA, an
effective TPMS is one that provides a warning before a dangerous
situation is imminent and which does not mislead motorists into
equating the absence of an illuminated warning light with safety.
BERU Corporation (BERU) commented that the under-inflation
detection level should be set to trigger a warning at either 25-percent
below placard pressure or a minimum activation pressure of 1.4 bar.
The Rubber Manufacturers Association (RMA) commented that lost fuel
efficiency was not adequately accounted for in the assessment of
economic costs when selecting an
[[Page 18146]]
under-inflation detection threshold. The RMA asserted that the NPRM's
benefits calculations indicated that 26 percent of vehicles have tires
that are under-inflated below placard pressure, but that associated
fuel efficiency costs were not considered.
The Specialty Equipment Market Association (SEMA) argued that TPMSs
should be reprogrammable in order to accommodate alternate and
replacement tires with different pressure thresholds, or alternatively,
the system could include ``smart'' software that would automatically
detect the proper pressure threshold. According to SEMA, as currently
proposed, when a higher-pressure tire is installed on the vehicle, the
TPMS would not indicate low tire pressure until the tire is 25-percent
below the value for the lower-pressure, original tire, and the converse
would also be a problem, with the telltale actuating prematurely when a
lower-pressure aftermarket tire is installed. SEMA stated that this
situation would defeat the intent of the rule, give drivers a false
sense of security, and be potentially problematic for new, low-profile
tires that may be easily damaged.
As part of the final rule, we have decided to retain the proposed
under-inflation detection level, by which the TPMS is required to
illuminate a low tire pressure warning telltale whenever the inflation
pressure in one or more of the vehicle's tires, up to a total of four
tires, is equal to or less than their the pressure 25 percent below the
vehicle manufacturer's recommended cold inflation pressure or the
pressure specified in the 3rd column of Table 1 of this standard for
the corresponding tire type, whichever is higher. We have reached this
determination for the following reasons.
Selecting an appropriate notification threshold level for the TPMS
is one of the most fundamental matters to be resolved as part of this
rulemaking. It involves balancing the safety benefits of alerting
consumers to low tire pressure against the risks of over-alerting them
to the point where the warning becomes a nuisance that may be ignored.
We believe that the final rule's 25-percent under-inflation detection
level strikes the proper balance in this regard.
As discussed in the June 5, 2002 final rule, NHTSA conducted a tire
pressure survey that inspected over 11,500 vehicles, which reported
that 26 percent of passenger cars and 29 percent of light trucks had at
least one tire that was 25 percent or more below the recommended
inflation pressure for that vehicle (see 67 FR 38704, 38713). However,
despite this substantial percentage of vehicles with under-inflated
tires at this level, incidents of tire failures remain infrequent.
NHTSA conducted testing on a variety of Standard Load P-metric tires at
20 psi with 100-percent load at 75 mph for 90 minutes on a dynamometer,
and none of these tires failed (see 67 FR 38704, 38726 (June 5, 2002)).
This testing led the agency to conclude that warnings at less severe
conditions will give drivers sufficient time to check and re-inflate
their vehicles' tires before the tires experience appreciable damage.
Accordingly, we believe that an under-inflation detection level of 25
percent would have a strong fleet impact, holding driver behavior
constant.
However, if we instead selected an under-inflation detection
threshold that is too stringent, with some commenters arguing for a
level as small as 1 or 2 psi below placard pressure, the warning
telltale might illuminate frequently, and the driver would need to
repeatedly stop and add a small amount of air to the tires in order to
extinguish the telltale. After servicing the tires in this manner for
the first few times, the driver might decide to postpone action on the
TPMS's warnings or ignore such warnings entirely. Thus, if the under-
inflation warning threshold were to be set too low, the safety benefits
associated with the TPMS's low pressure warning could be lost. Because
we have determined that a 25-percent under-inflation detection
threshold already provides a warning to the driver before adverse
safety consequences arise, providing a more stringent warning threshold
would not be expected to provide additional safety benefits, although
it could increase the risk of the nuisance warnings discussed above.
We disagree with Public Citizen's reading of the Court's decision
in Public Citizen v. Mineta, implying that the Court had somehow ruled
against NHTSA's development of a technology-neutral standard or its
consideration of costs as a part of the rulemaking. In fact, the Court
held that it was appropriate for NHTSA to consider costs as part of the
rulemaking, stating ``the agency was correct to consider the relative
costs,''\20\ although the Court disagreed with how the agency weighed
those costs in setting compliance options in the June 2002 final rule.
Furthermore, the Court specifically found the four-tire, 25-percent
under-inflation detection level to be reasonable. The Court held,
``Given that the 25 percent standard was a substantially more cost
effective means of preventing injuries and saving lives than the 20
percent standard, we conclude that it was reasonable for NHTSA to adopt
the former and reject the latter.''\21\
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\20\ Public Citizen v. Mineta, 340 F.3d 39, 57 (2d Cir. 2003).
\21\ Id. at 62.
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Available agency data show that a TPMS with a four-tire, 25-percent
under-inflation threshold is more cost-effective than one with a four-
tire, 20-percent under-inflation threshold. This issue was specifically
addressed in the Final Economic Assessment (FEA) for the June 2002
final rule, which found that the net cost per equivalent life saved for
a four-tire, 20-percent system would be $5.1-$5.3 million but that the
net cost per equivalent life saved for a four-tire, 25-percent system
would be $4.3 million.\22\ Although we realize that the precise values
of these figures are somewhat outdated, we believe that their cost-
effectiveness relative to each other has not changed significantly. For
additional information on the cost of alternative systems considered,
please consult the FEA and the Final Regulatory Impact Analysis (FRIA)
for this final rule, which has been included in the docket for this
rulemaking.
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\22\ See page iv of the FEA (Docket No. NHTSA-2000-8572-216).
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We are not adopting BERU's recommendations regarding the under-
inflation detection test procedures because BERU has not provided any
rationale to explain why the existing procedures are inadequate.
Regarding the issue of TPMS reprogrammability raised by SEMA, we
have decided to permit, but not require, such a feature. However, we
reiterate that we will conduct compliance testing with the tires
installed on the vehicle at the time of initial sale, and we will
follow manufacturer instructions for resetting the TPMS.
(b) Time Period for Low Pressure Detection. As noted above,
paragraph S4.2(a) of the NPRM proposed to require the TPMS to detect
and provide a warning to the driver within 10 minutes after a tire
becomes significantly under-inflated (i.e., reaches the warning
threshold specified in the standard). Under paragraph S4.2(b), the NPRM
proposed to require the low pressure telltale to continue to illuminate
as long as the pressure in any of the tires is equal to or less than
the activation threshold specified in S4.2(a) and the ignition locking
system is in the ``On'' (``Run'') position, whether or not the engine
is running. The NPRM proposed that the telltale must extinguish after
the inflation pressure is corrected.
A number of commenters urged NHTSA to modify this ten-minute
detection time requirement as part of
[[Page 18147]]
the final rule, with some commenters recommending a longer time period
and others recommending a shorter one.
Manufacturers that commented on low pressure detection time
generally recommended extending the time period. BMW of North America,
LLC (BMW) stated that the TPMS requirements should reflect real world
needs. As a result, BMW stated that the NPRM's 10-minute detection
requirement should be retained when only one tire becomes significantly
under-inflated (e.g., to detect situations where a tire is punctured by
a nail or sustains other damage that could result in a relatively rapid
loss of inflation pressure). BMW stated that when two, three, or all
four tires become significantly under-inflated at the same time, the
detection time requirement should be extended to 90 minutes, because
under-inflation in these circumstances is likely to result from slow
diffusion over months and is not likely to result in a problem
requiring immediate attention. NIRA Dynamics provided similar arguments
and reasoning, although it recommended a detection time of 20 minutes
for a single tire and at least one hour for multiple tires.
Sumitomo Rubber Industries (Sumitomo) offered a different
assessment of the time needed for low pressure detection. Sumitomo
stated that it is appropriate to maintain a 10-minute detection (and
extinguishment) requirement for one tire, but that a TPMS would need at
least 30 minutes (preferably one hour) to detect (and extinguish)
multiple under-inflated tires.
In its comments, Hyundai American Technical Center, Inc./ Kia
Motors Corporation (Hyundai) provided yet another recommendation
regarding low tire pressure detection time, stating that the time
period for detection and verification of low tire pressure under the
standard should be extended to at least 20 minutes. Hyundai stated that
delivery frequency for data from the direct TPMS tire pressure sensor
to the main control unit can take as long as three minutes, which is a
function of Federal Communications Commission (FCC) requirements \23\
that limit signal transmissions and the capacity of the battery in the
sensor. In addition, Hyundai stated that a number of transmissions may
be required to correctly diagnose low tire pressure. Therefore, if a
wireless data error occurs, Hyundai argued that the TPMS may not be
able to gather sufficient data within the NPRM's proposed 10-minute
time limit to assess the vehicle's tire pressures. Accordingly, Hyundai
argued that the final rule should permit at least 20 minutes for low
tire pressure detection in order to give the TPMS sufficient time to
gather enough data to make an accurate assessment.
---------------------------------------------------------------------------
\23\ See 47 CFR 15.231.
---------------------------------------------------------------------------
Volkswagen of America, Inc., Volkswagen AG, and Audi AG (VW/Audi)
commented that in order to overcome the technology-limiting
requirements of the NPRM, the final rule should permit a driving time
of up to one hour for the low tire pressure warning, a time period
consistent with detecting the unlikely situation where all four tires
become under-inflated due to slow air leakage or changes in ambient
temperature.
In contrast, other commenters argued that the NPRM's 10-minute
under-inflation detection time is too long and should be reduced.
Public Citizen argued that the requirement for under-inflation
detection time should be reduced to one minute in the final rule,
because direct TPMSs can meet such a requirement. Public Citizen stated
that in proposing a 10-minute under-inflation detection requirement,
NHTSA has unjustifiably lowered the bar in order to accommodate more
manufacturers (i.e., to permit indirect TPMSs requiring a longer time
period for detection).
ETV commented that the TPMS should be required to activate (and
extinguish) its warning within 10 seconds of vehicle start-up in order
to prevent the vehicle from entering traffic with a potentially
dangerous level of tire under-inflation.
The EC commented that the 10-minute detection time for the low tire
pressure warning does not adequately address the tire safety problem,
because during this period, the tire(s) may be operated at pressures
even lower than 25-percent below the recommended pressure and
significant structural damage could occur during that time period. The
EC expressed concern that a combination of high speed, a long
activation period, and a 25-percent under-inflation detection level
could significantly reduce the time available to the driver to take
appropriate action. (The European Tyre and Rim Technical Organisation
(ETRTO) provided a similar comment.) The RMA similarly objected to the
10-minute activation time period as being unsafe; the RMA argued that,
particularly at higher speeds, that activation time would allow the
vehicle to travel with under-inflated tires for many miles with
excessive heat, over-deflected body cords, and possible structural
damage.
According to Emtop Ltd. (Emtop), the NPRM's 10-minute under-
inflation detection requirement does not address the 15 percent of
incidents of under-inflation caused by rapid pressure drop (Emtop's
estimate). Emtop argued that the proposed requirement is dictated by
the inability of many current systems to meet a more stringent
requirement for detection time. Emtop stated that its TPMSs can detect
rapid pressure losses ``in a fraction of a second'' and that the TPMS
rule should not create barriers to such high-performance systems.
MLHO, Inc. (MLHO), which has developed a battery-less, non-radio-
frequency (RF) TPMS that relies on directional magnetic coupling to
send pressure information, commented that there is no need for a TPMS
to provide either an under-inflation warning or a malfunction warning
while the vehicle is stationary. (In simple terms, in the MLHO TPMS
system, wheel rotation powers the transmitter.) The commenter argued
that a very flat tire will be obvious to the driver or will trigger the
warning before the vehicle has traveled a significant distance. As to
the malfunction indication, MLHO argued that since a TPMS malfunction
does not constitute an emergency, the malfunction need not to be
detected prior to vehicle movement.
Instead, MLHO recommended that the proposed detection requirements
in S4.2 of the NPRM should be revised to require the TPMS to detect the
significantly under-inflated tire(s) and to illuminate the low tire
pressure telltale within 10 minutes after the vehicle is in motion
within the standard's designated speed range. MLHO requested that NHTSA
also include language in S4.2 to specify that the TPMS will not be
expected to either illuminate or extinguish the low tire pressure
telltale without the vehicle being in motion, as motion is necessary
for some systems to assess the vehicle's tire pressure status.
MLHO stated that as currently proposed, the NPRM imposes
unnecessary design restrictions, favors the ``present dominant RF-based
technology,'' and discriminates against small businesses.
NHTSA has carefully considered the commenters' countervailing
arguments regarding the time limit for the TPMS to detect a
significantly under-inflated tire, and we have decided to modify the
relevant requirement in this final rule. As revised, under S4.2 of the
standard, the TPMS must illuminate a low tire pressure warning telltale
not more than 20 minutes after the inflation pressure in one or more of
the vehicle's tires, up to a total of four tires, is equal to or less
[[Page 18148]]
than the pressure 25 percent below the vehicle manufacturer's
recommended cold inflation pressure or the pressure specified in the
3rd column of Table 1 of this standard for the corresponding tire type,
whichever is higher. We believe that this detection time period is
appropriate for the following reasons.
As noted in the agency's June 5, 2002 Federal Register notice,
TPMSs were not developed to warn the driver of extremely rapid pressure
losses that could accompany a vehicle encounter with a road hazard or a
tire blowout.\24\ According to the tire industry, those types of events
account for approximately 15 percent of pressure loss cases.\25\
Arguably, a driver would be well aware of the tire problem in those
situations, and the TPMS would provide little added benefit. Instead,
TPMSs' benefits lie in warning drivers when the pressure in the
vehicle's tires is approaching a level at which permanent tire damage
could be sustained as a result of heat buildup and tire failure is
possible; this low level of inflation pressure generally results from a
more measured pressure loss (produced over weeks or months) caused by a
slow leak, defective valve, or diffusion. According to the tire
industry, approximately 85 percent of all tire pressure losses are slow
air losses that occur over hours, weeks, or months of vehicle use.\26\
In those cases, a detection time of 20 minutes is not likely to pose a
safety risk to the driving public.
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\24\ 67 FR 38704, 38728 (June 5, 2002).
\25\ Id.
\26\ Id.
---------------------------------------------------------------------------
The agency's tire research suggests that even in a 25-percent
under-inflated condition, the vehicle can be operated safely for this
detection period without an appreciable risk of tire failure.
Specifically and as noted above, NHTSA conducted testing on a variety
of Standard Load P-metric tires at 20 psi with 100-percent load at 75
mph for 90 minutes on a dynamometer, and none of these tires
failed.\27\ This testing led the agency to conclude that warnings at
less severe conditions will give drivers sufficient time to check and
re-inflate their vehicles' tires before the tires experience
appreciable damage. Commenters advocating a reduced detection time did
not provide any evidence to demonstrate that operation of the vehicle
with one or more tires under-inflated by 25 percent leads to tire
damage or tire failure. Although manufacturers are encouraged to
provide the low tire pressure warning as quickly as possible, we
believe that a 20-minute detection period is unlikely to result in any
adverse safety consequences.
---------------------------------------------------------------------------
\27\ Id. at 38726.
---------------------------------------------------------------------------
We further believe that a change in the detection time is necessary
in order to articulate a standard that is practicable and technology-
neutral. According to manufacturers' comments, even direct TPMSs will
require additional time to detect and verify low tire pressure, in part
as a result of FCC regulations limiting the frequency of electronic
transmissions.
Furthermore, we anticipate that the extended time period also will
ease compliance for indirect systems (particularly when detecting
multiple under-inflated tires). Most indirect and hybrid TPMSs cannot
currently meet the four-tire, 25-percent under-inflation detection
threshold within 20 minutes. However, we are aware of at least one
indirect TPMS that is currently capable of doing so,\28\ and we expect
that with additional time and effort, other indirect and hybrid systems
also would be able to meet the requirements of the standard.
---------------------------------------------------------------------------
\28\ Docket No. NHTSA-2004-19054-96.
---------------------------------------------------------------------------
In sum, without an extension of the time period for low tire
pressure detection and warning, the number of TPMS technologies
available for use under the standard may be significantly curtailed.
Available information does not demonstrate a safety need for imposing
such limitations, and we believe that drivers would operate the vehicle
for 20-minutes periods with some frequency. For these reasons, we
believe that a 20-minute detection time period is both practicable and
meets the need for motor vehicle safety.
We have decided not to extend the low tire pressure detection time
beyond 20 minutes, however, as requested by some manufacturers in their
comments. Available research shows that 75 percent of commuters
regularly experience commute times of 30 minutes or less.\29\ A recent
study by the U.S. Census Bureau, using 2002 survey data, found that
average commute times for most major U.S. cities range from 20 to 30
minutes.\30\ Many other trips, such as routine errands, may also
involve drive times of less than 30 minutes. Therefore, if we were to
require a low tire pressure detection time of 30 minutes or more, it is
conceivable that consumers could be driving on significantly under-
inflated tires for a potentially extended period of time without
receiving a warning from the TPMS.
---------------------------------------------------------------------------
\29\ This statistic is based upon the results of a Washington
Post-ABC News-Time poll conducted by telephone from January 27-31,
2005 among 1,204 randomly selected adults nationwide. Results of
this poll were reported in the Washington Post on February 13, 2005,
at page A1.
\30\ See http://frwebgate.access.gpo.gov/cgi-bin/leaving.cgi?from=leavingFR.html&log=linklog&to=http://www.census.gov/acs/www/Products/Ranking/2002/R04T160.htm.
---------------------------------------------------------------------------
In addition, we are concerned that extending low pressure detection
time period beyond 20 minutes could be problematic in other situations.
For example, where a tire is punctured by a nail or is otherwise
damaged and may experience a moderately rapid pressure loss. As to
damaged tires but experiencing a relatively less rapid pressure loss,
research into the rate of temperature buildup shows that for constant
load, pressure, and speed conditions, tires generally warmed up and
stabilized their temperatures within 15 minutes of testing;\31\ thus,
the tire will rapidly reach a temperature that places stress on an
under-inflated tire. In both of those cases, we are concerned that a
30-minute detection time could delay the warning to the driver too
long. For these reasons, we have decided that a requirement that would
permit a low tire pressure detection time longer than 20 minutes could
diminish the overall utility of the TPMS and concomitantly reduce the
safety benefits associated with that system.
---------------------------------------------------------------------------
\31\ See June 5, 2002 comments of the Rubber Manufacturers
Association (Docket No. NHTSA-00-8011-64).
---------------------------------------------------------------------------
In response to the concerns of MLHO, it was never the agency's
intention to require detection absent vehicle motion. As demonstrated
by the standard's test procedures, the detection time for low tire
pressure includes a period of vehicle operation within a designated
speed range (see S6(f)). This provision for vehicular motion is already
built in to the general requirements of S4.1, which provides that the
TPMS must meet the detection requirements of S4 under the test
conditions specified in S5 and the test procedures specified in S6 of
the standard. We believe that no further modifications to the standard
are necessary related to this point.
2. TPMS Malfunction Indicator Lamp (MIL) Activation Requirements
Paragraph S4.4 of the NPRM proposed to require each covered vehicle
to be equipped with a TPMS that includes a telltale that illuminates
whenever there is a malfunction that affects the generation or
transmission of control or response signals in the TPMS and
extinguishes when the malfunction has been corrected.
The NPRM's proposed requirement for a TPMS Malfunction Indicator
Lamp (MIL) was not included in earlier rounds of the TPMS rulemaking
process. Consequently, the agency
[[Page 18149]]
expected and did receive extensive public comment on this proposed
provision. Commenters offered recommendations regarding how quickly the
TPMS must detect system malfunctions, the types of functions to be
detected, and the test procedures for detecting such malfunctions. Each
of these topics will be discussed in turn.
(a) Time Period for Malfunction Detection. The NPRM did not specify
a time period for the TPMS to detect a malfunction and to illuminate
the TPMS MIL.
The Association of International Automobile Manufacturers, Inc.
(AIAM) expressed concern that the NPRM would require detection and
notification of a TPMS malfunction immediately upon occurrence.
However, AIAM stated that immediate detection is not possible in most
cases, because TPMSs generally require the vehicle to be in motion in
order to detect a malfunction (an argument also raised by Honda Motor
Co., Ltd. and American Honda Motor Co., Inc. (Honda) and EnTire), and
several transmissions from the pressure sensor to the controller are
required to validate the existence of a malfunction.
AIMA stated that the FCC requires a pause between signal
transmissions at least 30 times as long as the signal transmission
itself. In addition, AIMA stated that interference may result in the
loss of some of these signals. AIMA argued that a requirement for
immediate detection and reporting of a TPMS malfunction could result in
many false positive warnings, which could undermine consumers' faith in
the system and potentially lead them to ignore TPMS-related warnings
(an argument repeated by General Motors North America (GM) and Hyundai
in their comments). In light of the above, AIMA recommended that the
agency allow the TPMS between 30 and 60 minutes to determine with a
high degree of certainty whether a true malfunction is present (e.g.,
not one caused by signals external to the vehicle). The Alliance made a
similar comment, suggesting a 30-minute detection time for a
malfunction.
Several other commenters also recommended that the agency specify a
time period for the detection of a TPMS malfunction, although the
recommended time periods varied. For example, ALPS Automotive, Inc.
(ALPS) and Honda commented that a TPMS cannot detect malfunctions any
faster than the system can detect low tire pressure and that the same
durational parameters should be set for both functions. ALPS, BERU,
Schrader Electronics, Ltd. (Schrader), and Fuji Heavy Industries USA,
Inc. (Fuji) each recommended a 10-minute detection time. BERU stated
that it does not support an ``excessive[ly] long'' duration for TPMS
malfunction detection, because an extended ride (even 20 minutes) with
a defective TPMS or an incompatible tire could prevent a low pressure
warning and lead to a tire blow out. BERU also recommended
specification of a vehicle moving distance. BERU stated that
specifications for ``duration'' and ``vehicle moving distance'' are
necessary not only for the detection of a malfunction, but also for the
validation of the correction of a malfunction.
EnTire and Hyundai recommended a malfunction detection time of 20
minutes. According to EnTire, if a pressure sensor is disabled, it can
take over 13.5 minutes for the fault to ``mature'' and to be detected
by the system and suggested 20 minutes as a reasonable detection time.
(EnTire also suggested 20 minutes as a reasonable extinguishment time
for the MIL, and Fuji recommended that a vehicle be driven at least 10
minutes at a minimum of 40 kph in order to verify that the malfunction
has been eliminated.) Hyundai commented that current direct TPMSs are
designed so that a failure is recognized only when the control unit
does not receive data from the pressure sensor for three to four
consecutive delivery cycles. Hyundai stated that current systems,
therefore, require approximately 20 minutes to properly detect and
verify TPMS malfunctions, a time period consistent with minimization of
nuisance warnings.
GM recommended a 30-minute drive time for TPMS malfunction
detection. GM stated that the MILs for its current TPMSs have a 25-
minute drive period for the detection threshold, and the company is not
aware of any consumer complaints arising from delayed TPMS malfunction
warnings. GM argued that a TPMS that is programmed to be highly
reactive in terms of malfunction detection and that provides an
immediate response may result in relatively frequent malfunction
warnings because common, everyday occurrences are likely to temporarily
disturb the TPMS's signals.
MLHO stated that the regulatory text related to the TPMS
malfunction detection requirement should be revised to focus on the
detection of a malfunction or correction of a malfunction, rather than
the occurrence of those events. MLHO's comment is related to those
about the need for the system to have adequate time to detection the
presence or absence of a malfunction.
DaimlerChrysler Corporation (DaimlerChrysler) made a general
argument that NHTSA has not calculated or otherwise demonstrated any
significant safety benefits associated with the TPMS MIL.
Based upon the information provided by the commenters, we have
decided to modify our approach to the MIL by providing a time period
for malfunction detection and a speed range in which the vehicle will
be driven as part of the malfunction detection phase in the test
procedures. Specifically, this final rule requires the TPMS to detect a
malfunction and to illuminate the MIL within 20 minutes of the
occurrence of a malfunction, when the vehicle is driven at a speed
between 50 km/h and 100 km/hr.
Several commenters have stated that TPMSs generally require the
same amount of time to detect and to verify a malfunction as they do
for low tire pressure. As discussed above, the detection time period
for low tire pressure has been increased to 20 minutes. A number of
commenters stated that 20 minutes would provide adequate time for TPMS
malfunction detection, with some commenters recommending an even
shorter time period (e.g., 10 minutes). We also believe that specifying
a time period for detection addresses MLHO's comment that the standard
should not imply a requirement for automatic illumination of the MIL as
soon as a malfunction occurs.
We understand that certain TPMS technologies require vehicular
motion in order to diagnose a TPMS malfunction, which is similar to the
way in which such systems detect low tire pressure. For that reason, we
are now specifying in the standard's test procedures that the vehicle
will be driving within a designated speed range during the malfunction
detection phase.
We see important benefits in including a MIL requirement as part of
the final rule. First, the malfunction detection requirement is
intended to ensure the long-term functionality of the TPMS by
identifying those small number of replacement tires with construction
characteristics that would prevent proper operation of the TPMS.
Without the TPMS MIL, some drivers would lose the benefit of the low
tire pressure warning to be provided by the TPMS. The malfunction
indicator was recommended by the Alliance as a solution to this
problem. In addition, the MIL could provide ancillary benefits by
alerting the driver of other situations where the system becomes non-
operational; in some cases, the problem may be temporary (e.g., brief
signal
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disturbance), but in other cases, the MIL may signal the need for
repair of the TPMS. In all these cases, it is useful to the driver to
be aware that the system is unavailable to provide a low tire pressure
warning.
However, with the above said, we do believe that the above
accommodations can be made without any significant decrease in safety
benefits. A TPMS malfunction does not itself represent a safety risk to
vehicle occupants, and we expect that the chances of having a TPMS
malfunction and a significantly under-inflated tire at the same time
are unlikely. Even if that is the case, we do not believe that a 20-
minute detection time would increase occupant risk appreciably.
(b) What Constitutes a TPMS Malfunction? The NPRM proposed to
require the MIL to illuminate ``whenever there is a malfunction that
affects the generation or transmission of control or response signals
in the vehicle's tire pressure monitoring system'' and to extinguish
when such malfunction is corrected (S4.4(a)).
A number of commenters argued that proposed malfunction requirement
is overly broad and in need of modification. The Alliance, the
organization that originally suggested consideration of a TPMS MIL,
stated that it remains committed to providing an in-vehicle indication
when there is inadequate signal reception from one or more TPMS
sensors. However, the Alliance stated that the technical specifications
for the MIL proposed in the NPRM are different than the MILs that
Alliance members were expecting and, in some cases, are inconsistent
with the MILs that manufacturers are already voluntarily providing.
Fuji stated that although it is reasonable to require malfunction
detection for components that sense and transmit tire inflation
pressure data, the standard should only require malfunction detection
and warning in three situations: (1) When there is inadequate (or no)
input signal from the wheel sensors; (2) when there is inadequate (or
no) input signal from the antenna to the electronic control module
(ECM), or (3) when there is inadequate (or no) input signal from other
systems used by the malfunction warning system (e.g., ABS wheel speed
input to the ECM). Fuji stated that malfunctions in the TPMS ECM (which
contains the logic to determine that a malfunction exists) would be
impossible to indicate via the MIL, because the module would not be
functioning to operate the lamp.
Sumitomo commented that paragraph S4.4, as proposed, should be
modified to require the TPMS to indicate a malfunction under the
following two conditions: (1) When wheel speed signals cannot be
transmitted from wheel speed sensors to the TPMS, and (2) when tire
pressure signals cannot be transmitted from the pressure sensors to the
TPMS.
ETV stated that the MIL should indicate the following malfunctions:
(1) Incompatibility of replacement tires/rims; (2) sensor failure; (3)
signal failure in communications channel; (4) reader electronics
failure, and (5) telltale bulb failure. ETV argued that there should be
a redundancy or failsafe built into the system so that a burnt out
telltale bulb can still produce a malfunction warning, so as to alert
the consumer that that bulb needs replacement.
Hyundai stated that there are three types of TPMS malfunctions that
will require addition of a separate electrical circuit to activate the
MIL: (1) Disconnection of the power source to the main control unit;
(2) disconnection of the power source to the telltale lamp, and (3)
disconnection of wiring between the main control unit and the telltale
lamp. Hyundai requested that the agency exclude these three
malfunctions from the requirements of the standard during the phase-in
period, because incorporating detection capabilities for these types of
malfunctions would require additional development time. Alternatively,
Hyundai suggested that detection of these conditions could be achieved
through the bulb check function and supplemental language in the
owner's manual; in those cases, the TPMS lamp would not be illuminated
during the bulb check, and the driver would consult the owner's manual
to be alerted to the TPMS malfunction in such cases.
In addition, Hyundai stated that even though components such as the
electronic control unit (ECU) or vehicle speed sensors are involved in
TPMS operation, failure of these components should not be considered a
TPMS malfunction. Mitsubishi stated that the MIL should not be required
to provide a warning during brief interruption of communication between
sensors and the ECU because the TPMS uses radio communications that can
be affected by external interference; this is a common occurrence that
could result in false positive warnings. GM made a similar point about
not requiring the TPMS MIL to illuminate during brief and temporary
interruption of signals.
The comments of American Suzuki Motor Corporation (Suzuki)
discussed the malfunction detection capabilities of the TPMS currently
installed on the Suzuki XL-7. According to Suzuki, that system provides
a malfunction indication when there is either a loss of power to the
TPMS control unit or when there is no electrical connection between the
control unit and the TPMS telltale. Suzuki stated that although its
system is not compliant with the NPRM's proposed MIL requirements, it
believes that its system is just as effective as the MIL technical
specifications in the NPRM. Therefore, Suzuki requested that NHTSA
adopt ``less design-restrictive'' requirements for the TPMS MIL, so as
to allow continued use of its system.
NIRA Dynamics commented that it is important to keep the
malfunction indicator requirements generic, so that any TPMS technology
may be used. As examples of limitations specific to certain types of
TPMS technology, NIRA Dynamics stated that: (1) Many direct systems
cannot detect a malfunction when the vehicle is stationary if the
sensor does not have any contact with the receiver due to wheel angle;
(2) it is impossible for indirect systems to detect a malfunction when
the vehicle is stationary because the wheel must rotate to diagnose the
sensor, and (3) indirect systems cannot detect tire incompatibilities.
NIRA Dynamics urged that the final rule should simply require TPMSs to
be designed to detect malfunctions ``according to good engineering
practices.''
Honda's comments sought confirmation that the following system
failures would be excluded from the TPMS MIL activation and warning
requirements: TPMS indicator light, TPMS coupler, and meter panel.
Honda argued that it would be unnecessary for the TPMS MIL to report
these failures because they would be apparent upon bulb check. Honda
also requested that the agency issue a laboratory test procedure for
generating a TPMS system fault, so as to clear up any confusion related
to the types of malfunctions that will be subject to testing.
Continental Teves, Inc. (Continental Teves) also commented that for
a hybrid system, it would not be possible for the TPMS to illuminate
the MIL to indicate an incompatible tire unless it is on a wheel with a
pressure sensor. Continental Teves stated that the TPMS MIL should not
be required to illuminate when an incompatible replacement tire is
installed, but instead, the system should be permitted to continue to
function with reduced performance without the MIL being lit. BMW also
stated that the TPMS MIL should not be required to illuminate when
system failure is the result of a change to an incompatible tire,
because
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such failure is not the result of a malfunction of the TPMS.
Schrader commented that the TPMS should not be required to signal a
malfunction when the ignition locking system is in the lamp-check
position, because that status check should be reserved for confirming
the functionality of the telltale bulb.
After careful consideration of the public comments, we have decided
to retain the NPRM's requirement for the MIL to illuminate whenever
there is a malfunction that affects the generation or transmission of
control or response signals in the vehicle's tire pressure monitoring
system. Although the commenters expressed preferences for TPMSs with
reduced malfunction detection capabilities, they did not state that it
would be impracticable to provide the proposed warnings. Furthermore,
we believe that, given adequate lead time, this requirement is
practicable, because a nearly identical malfunction requirement for
anti-lock braking systems (ABS) is contained in FMVSS No. 121, Air
Brake Systems, and vehicle manufacturers have certified to that
standard successfully. We expect that manufacturers would similarly be
able to meet the malfunction detection requirements of the TPMS
standard.
As drafted, the TPMS malfunction detection requirement is
technology-neutral and capable of accommodating system design changes
without the need to continually amend the standard. For example, in a
direct TPMS, the control signals are generated by the wheel sensor and
transmitted to an electronic control unit via an antenna. In contrast,
in an indirect TPMS, the control signals may be generated by the ABS
wheel sensor and transmitted to the electronic control unit directly.
The present requirement encompasses both types of systems.
In response to comments suggesting that the TPMS MIL should only
detect specific malfunctions, the agency believes that such
restrictions would unnecessarily reduce the safety benefits of the
TPMS. Specifications in the standard that would limit malfunctions that
must be detected could impose design restrictions on manufacturers
because such specifications and the components to which they refer may
not be applicable to current or future TPMS designs. The agency
recognizes that the requirement for malfunction detection includes all
TPMS components and may require some additional circuitry and software,
but we believe that with minor modifications, it would be practicable
to monitor all TPMS components for malfunction. Therefore, we are not
adopting the specific limitations recommended by the commenters.
We agree with the comment of Schrader that the MIL should not be
required to signal a burned out bulb as a TPMS malfunction, because
that problem would already be identified during the check-of-lamp
function at vehicle start-up.
As discussed previously, we recognize that most TPMSs require
vehicular motion in order to detect a system malfunction, so we have
incorporated a 20-minute drive time in a designated speed range as part
of