Mr. Brian Latouf
Director, Safety Regulations and Consumer Information
General Motors North America
Mail Code 480-111-S56
30200 Mound Road
Warren, MI 48090-9010
Dear Mr. Latouf:
This responds to your letter concerning a February 6, 2007 final rule amending Federal Motor Vehicle Safety Standard (FMVSS) No. 206, Door Locks and Door Retention Components. You ask about the door locks requirements for back doors, particularly S4.3.1 and S4.3.2s requirement for separate actions to unlock the door and operate the interior latch release control. You also ask about unlatching doors via a remote transmitter (key fob).
In your letter, you do not discuss in detail the back doors to which you are referring. For purposes of this letter, we assume, based on informal conversations with you and other General Motors (GM) representatives, that your questions about the door locks requirements are concerning hatchback/station wagon back doors and lift gates on sport utility vehicles, i.e., hinged back doors that open a cargo compartment that does not have a partition between the cargo space and the last row of forward-facing seats. As discussed below, these types of back doors are subject to current door lock requirements as well as to the amended door locks requirements for back doors.
The February 6, 2007 final rule amended and updated requirements and test procedures of FMVSS No. 206, and harmonized with the worlds first global technical regulation (GTR) for motor vehicles (72 FR 5385). (The effective date of the final rule is
September 1, 2009; there are pending petitions for reconsideration of the final rule. Docket No. NHTSA-2006-23882.) To prevent inadvertent rear side and back door openings, the amended standard specifies, among other requirements:
S4.3.1 Rear side doors. Each rear side door shall be equipped with at least one locking device which has a lock release/engagement mechanism located within the interior of the vehicle and readily accessible to the driver of the vehicle or an occupant seated adjacent to the door, and which, when
engaged, prevents operation of the interior door handle or other interior latch release control and requires separate actions to unlock the door and operate the interior door handle or other interior latch release control.
S4.3.2 Back doors. Each back door equipped with an interior door handle or other interior latch release control, shall be equipped with at least one locking device that meets the requirements of S4.3.1.
Paragraph S4 states that these amended requirements apply to all side and back doors, that lead directly into a compartment that contains one or more seating accommodations and the associated door components .
You state that, because the GM back doors at issue do not have interior door handles and do not lead directly into a compartment that contains one or more seating accommodations, hinged back doors that open a cargo compartment that does not have a partition between the cargo space and the last row of forward-facing seats should not be subject to amended FMVSS No. 206. We disagree. Where there is no partition between such a cargo compartment and the passenger compartment, there is a risk that unbelted passengers could be ejected through the gap and through the rear window (see, e.g., the definition of back door in S3 of the standard; the September 28, 1995 final rule extending FMVSS No. 206 to back doors of passenger cars and MPVs so equipped, including hatchbacks, station wagons, sport utility vehicles, and passenger vans with a [gross vehicle weight rating] of 4,536 kg (10,000 pounds) or less (60 FR 50124, 50127); and a May 2, 2007 letter to Lance Tunick, copy enclosed). Since preventing injuries resulting from such an event is one of the primary purposes of FMVSS No. 206, the agencys position is that such back doors are considered leading directly into a compartment that contains one or more seating accommodations and, thus, such back doors must meet amended FMVSS No. 206 door lock requirements in paragraph S4.3.2.
Since the GM doors at issue must comply with door locks requirements for back doors (S4.3.2), the requisite interior lock release/engagement mechanism for a back door must, when engaged, require separate actions to unlock the door and operate the interior latch release control.
Separate Action to Unlock
You ask about the permissibility of a permanently mounted switch located in the proximity of the driver which when pushed results in the unlatching of the back door. This switch is only operable when the vehicle is stationary (i.e., placed in park for vehicles with automatic transmission), or moving less than 3 kilometers/hour (km/h) for vehicles with manual transmissions.
We would consider this driver-side back door release button to be an interior latch release control. As such, per S4.3.1 and S4.3.2, when the back door is locked, there must be separate actions to unlock the door and operate the interior latch release control. The question you raise is whether placing a vehicle in park (for vehicles with automatic transmissions), or moving less than 3 km/h (for vehicles with manual transmissions) satisfies this requirement.
Although NHTSA has not addressed which types of actions are permissible separate actions, the agency explained that the door lock requirements for rear and back doors are in place to reduce inadvertent door openings due to impact upon or movement of the inside or outside door handle. 33 FR 6465 (April 27, 1968); 72 FR at 5395. Thus, the safety concern this requirement intends to mitigate is risk of ejection from a moving vehicle through inadvertent rear and back door openings. We have analyzed your system with this safety risk in mind.
The following observations bear on the safety risks at issue. According to your letter, in a vehicle with an automatic transmission, the precondition for the driver-side button to be operable is that the vehicle must be placed in park. Since the vehicle will be in park, the relevant safety concern (ejection risk) is not present when this driver-side back door release button is operable (able to open the door) because the vehicle is not in motion. However, in vehicles with manual transmissions, the driver-side back door release button that you describe in your letter is operable when the vehicle is in motion (when the vehicle is going 3 km/h or less). Thus, ejection risk may still be present where a driver-side back door release button is operable by a single push when the vehicle is in motion.
We now turn to the requirement of separate actions to unlock the door and operate theinterior latch release control (driver-side back door release button). Because the requirement addresses a concern of inadvertent door openings, we conclude that S4.3.1 requires a separate, discrete action on the part of the consumer indicating a definitive decision, or intent, to unlock the door. The separate actions required by S4.3.1--particularly, for your letter, the action to unlock the door--should be distinct from the actions that a driver normally uses to drive a vehicle, and should be purposeful toward unlocking the door and consistent with an intent to egress. Otherwise, the consumer may not know that the door has been unlocked in the course of executing normal driving actions. If there is a discrete action separate from the normal motions of driving, it is less likely a door will be inadvertently opened.
Automatic Transmission Vehicles
For these reasons, we interpret the amended FMVSS No. 206 door lock requirements to permit the system you describe for the automatic transmission vehicles, where a vehicle is placed in park, and the driver-side single-hold switch unlatches the back door. Placing an automatic transmission vehicle in park is a distinct action done when the vehicle is parked and indicates intent to egress the vehicle. Placing an automatic transmission vehicle in park is not a driving motion.
We acknowledge that placing your vehicle in park does not actually unlock the back door of the vehicles you describe (i.e., if the back door is locked while the vehicle is in motion, it will remain incapable of being opened from inside or outside after the vehicle is placed into park). However, the conventional understanding of separate actions to unlock the door and operate the interior door handle or other interior latch release control is the actuation of a plunger or other unlocking mechanism followed by the actuation of the door handle. The first action (actuation of the plunger) is the action to unlock the door, and the second action (actuation of the door handle) is the action that operates the interior latch release control. With your vehicle, the action of placing a vehicle in park is arguably a better indication that the relevant safety concern (ejection risk) is no longer present than the conventional first separate action, actuation of a plunger. A vehicle can only be placed in park when it has come to a complete stop, whereas a conventional plunger can be actuated while the vehicle is in motion. Accordingly, NHTSA considers placing a vehicle in park to be functionally equivalent to a separate action to unlock the door. Thus, we conclude that the driver-side switch you describe in your letter meets the separate action requirements of S4.3.1 for automatic transmission vehicles where the driver-side back door release button is inoperable unless the vehicle is placed in park.
Standard Transmission Vehicles
In contrast, we do not interpret the door lock requirements to permit such a driver-side switch in the manual transmission vehicles you described, because we do not consider the mere act of braking to 3 km/h to be a distinct action separate from the common actions a driver engages in while operating a vehicle in normal use. Braking to 3 km/h is not a discrete, or individually distinct, action indicating that the vehicle is being parked. Additionally, braking to 3 km/h does not indicate any intent to egress the vehicle. It is a motion a driver engages in while operating a vehicle in normal use. Accordingly, we do not interpret the operability of a switch to unlatch a back door while moving less than 3 km/h to be compliant with S4.3.1s requirement for separate actions to unlock the door, and operate the interior latch release control.
Regarding remote transmitters (key fobs), FMVSS No. 206 does not currently address key fobs and, thus, does not prohibit a single-hold function that both unlocks and unlatches a back door lock. However, the National Highway Traffic Safety Administration (NHTSA) does not rule out the possibility of such door lock controls being regulated in the future.
If you have any further questions, please do not hesitate to contact Sarah Alves of my staff at (202) 366-2992.
Stephen P. Wood
Acting Chief Counsel