NHTSA Interpretation File Search
Overview
NHTSA's Chief Counsel interprets the statutes that the agency administers and the standards and regulations that it issues. Members of the public may submit requests for interpretation, and the Chief Counsel will respond with a letter of interpretation. These interpretation letters look at the particular facts presented in the question and explain the agency’s opinion on how the law applies given those facts. These letters of interpretation are guidance documents. They do not have the force and effect of law and are not meant to bind the public in any way. They are intended only to provide information to the public regarding existing requirements under the law or agency policies.
Understanding NHTSA’s Online Interpretation Files
NHTSA makes its letters of interpretation available to the public on this webpage.
An interpretation letter represents the opinion of the Chief Counsel based on the facts of individual cases at the time the letter was written. While these letters may be helpful in determining how the agency might answer a question that another person has if that question is similar to a previously considered question, do not assume that a prior interpretation will necessarily apply to your situation.
- Your facts may be sufficiently different from those presented in prior interpretations, such that the agency's answer to you might be different from the answer in the prior interpretation letter;
- Your situation may be completely new to the agency and not addressed in an existing interpretation letter;
- The agency's safety standards or regulations may have changed since the prior interpretation letter was written so that the agency's prior interpretation no longer applies; or
- Some combination of the above, or other, factors.
Searching NHTSA’s Online Interpretation Files
Before beginning a search, it’s important to understand how this online search works. Below we provide some examples of searches you can run. In some cases, the search results may include words similar to what you searched because it utilizes a fuzzy search algorithm.
Single word search
Example: car
Result: Any document containing that word.
Multiple word search
Example: car seat requirements
Result: Any document containing any of these words.
Connector word search
Example: car AND seat AND requirements
Result: Any document containing all of these words.
Note: Search operators such as AND or OR must be in all capital letters.
Phrase in double quotes
Example: "headlamp function"
Result: Any document with that phrase.
Conjunctive search
Example: functionally AND minima
Result: Any document with both of those words.
Wildcard
Example: headl*
Result: Any document with a word beginning with those letters (e.g., headlamp, headlight, headlamps).
Example: no*compl*
Result: Any document beginning with the letters “no” followed by the letters “compl” (e.g., noncompliance, non-complying).
Not
Example: headlamp NOT crash
Result: Any document containing the word “headlamp” and not the word “crash.”
Complex searches
You can combine search operators to write more targeted searches.
Note: The database does not currently support phrase searches with wildcards (e.g., “make* inoperative”).
Example: Headl* AND (supplement* OR auxiliary OR impair*)
Result: Any document containing words that are variants of “headlamp” (headlamp, headlights, etc.) and also containing a variant of “supplement” (supplement, supplemental, etc.) or “impair” (impair, impairment, etc.) or the word “auxiliary.”
Search Tool
NHTSA's Interpretation Files Search
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ID: aiam5060OpenMs. Mindy Lang Division Manager Huntleigh Transportation Services Inc. #12 Millpark Court Maryland Heights, MO 63043; Ms. Mindy Lang Division Manager Huntleigh Transportation Services Inc. #12 Millpark Court Maryland Heights MO 63043; "Dear Ms. Lang: This responds to your letter of September 12, 1992 requesting information on regulations concerning bus conversions. Your company converts the interior of buses by installing such materials as carpets, wall coverings, and blinds. In particular you asked for information on regulations concerning the attachment of seats to vehicles and the material used for the construction of seats. I am pleased to have this opportunity to explain our law and regulations to you. The National Traffic and Motor Vehicle Safety Act (the Safety Act, 15 U.S.C. 1381 et seq.) authorizes this agency to issue Federal motor vehicle safety standards applicable to new motor vehicles and new items of motor vehicle equipment. Section 108(a)(1)(A) of the Safety Act (15 U.S.C. 1397(a)(1)(A)) prohibits any person from manufacturing, introducing into commerce, selling, or importing any new motor vehicle or item of motor vehicle equipment unless the vehicle or equipment item is in conformity with all applicable safety standards. NHTSA, however, does not approve motor vehicles or motor vehicle equipment, nor do we endorse any commercial products. Instead, the Safety Act establishes a 'self-certification' process under which each manufacturer is responsible for certifying that its products meet all applicable safety standards. NHTSA has exercised its authority to establish one safety standard relevant to seating, Standard No. 207, Seating Systems, which establishes strength and other performance requirements for vehicle seats. However, this standard excludes passenger seats on buses from these performance requirements. There is one other safety standard that could be affected by the work your company performs. Standard No. 302, Flammability of Interior Materials, specifies burn resistance requirements for materials used in motor vehicles, including buses. If your company converts previously certified buses, it could be considered an alterer under our regulations. Under 49 CFR Part 567, Certification, an alterer is defined as: A person who alters a vehicle that has been previously certified ... other than by the addition, substitution, or removal of readily attachable components such as mirrors or tire and rim assemblies, or minor finishing operations such as painting, ... before the first purchase of the vehicle in good faith for purposes other than resale .... If considered an alterer, your company would be subject to the certification requirements of 49 CFR 567.7. These requirements include provisions that the alterer supplement the original manufacturer's certification label, which must remain on the vehicle, by affixing an additional label. The label must state that the vehicle as altered conforms to all applicable Federal motor vehicle safety standards, including Standard No. 302. The label must also state the name of the alterer and the month and the year in which the alterations were completed. Your company would not be subject to the certification requirements of 49 CFR 567.7 if the modifications involve only readily attachable components. However, the modifications would still be affected by section 108(a)(2)(A) of the Safety Act. That section provides that: No manufacturer, distributor, dealer, or motor vehicle repair business shall knowingly render inoperative, in whole or in part, any device or element of design installed on or in a motor vehicle . . . in compliance with an applicable Federal motor vehicle safety standard. Any violation of this 'render inoperative' prohibition would subject the violator to a potential civil penalty of up to $1,000 for each violation. I hope you find this information helpful. I have enclosed an information sheet for new manufacturers of motor vehicle equipment that briefly explains the responsibilities imposed on manufacturers, and tells how to get copies of the relevant laws and regulations. If you have any other questions, please contact Mary Versailles of my staff at this address or by phone at (202) 366-2992. Sincerely, Paul Jackson Rice Chief Counsel Enclosure"; |
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ID: aiam0798OpenMr. Thomas L. Schroeder, Thoroughbred Homes, Inc., P.O. Box 1728, Valdoeta, GA 31601; Mr. Thomas L. Schroeder Thoroughbred Homes Inc. P.O. Box 1728 Valdoeta GA 31601; Dear Mr. Schroeder: This is in response to your inquiry of July 26, 1972, concerning th application of defect reporting requirements to mobile home manufacturers.; Although mobile homes are not specifically mentioned in the Nationa Traffic and Motor Vehicle Safety Act, they are considered to be motor vehicles subject to the Act. Because of their unique characteristics, mobile homes have been categorized as a separate vehicle type, 'mobile structure trailer,' under the motor vehicle safety standards 49 CFR Part 581. 'Mobile structure trailer' is defined in section 571.3 of that part.; The Defect Reports regulations (49 CFR Part 573) apply to manufacturer of all types of motor vehicles, including mobile structure trailers. They require manufacturers to report the number of vehicles manufactured during each calendar quarter. The description of the regulation's requirements in the article you enclosed is somewhat incomplete and accordingly we have enclosed a copy of the regulation for your guidance.; There are no specific forms which we require to be used in th submission of the specified information. Copies of acceptable formats you may wish to use, however, are also enclosed.; Yours truly, Richard B. Dyson |
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ID: aiam0262OpenMr. Gerald Sagerman, U.S. Agent, TVR Engineering, Ltd., 572 Merrick Road, Lynbrook, NY 11563; Mr. Gerald Sagerman U.S. Agent TVR Engineering Ltd. 572 Merrick Road Lynbrook NY 11563; Dear Mr. Sagerman: This is in response to your letter of October 14, 1970, to the Directo of the National Highway Safety Bureau forwarding information sheets on the TVR Vixen. I am enclosing copies of the Bureau's Consumer Information Regulations (49 CFR Part 575). The substantive provisions, S 575.101 on vehicle stopping distance, S 575.102 on tire reserve load, and S 575.106 on acceleration and passing ability, require the furnishing of specific information in a format which is in the form set out in the regulations. The information sheets which you have provided fall short of these requirements in both form and substance. For example, S 575.101 requires furnishing information on the minimum stopping distance, expressed in feet, for the particular vehicle, from a particular speed, at specified loads, with the braking system in a specified condition. The information provided by you in this regard is incomplete, and is not in the form specified. In addition, the regulations require the information to describe and be valid for each of the vehicles with which it is provided.; Please study the enclosed regulations carefully and forward to u complying consumer information within the near future. Let us know if you need further assistance.; Sincerely, Rodolfo A. Diaz, Acting Associate Director, Motor Vehicl Programs; |
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ID: aiam5430OpenMr. Richard J. Quigley 5886-b Fernflat Road Aptos, CA 95003; Mr. Richard J. Quigley 5886-b Fernflat Road Aptos CA 95003; Dear Mr. Quigley: This responds to your request for reconsideration o our July 15, 1994 interpretation letter on Standard No. 218, Motorcycle helmets. In that letter, we stated that a drawing you provided would not meet the requirement in S5.6.1(e) of the standard that motorcycle helmets be labeled with the symbol DOT. You enclosed a new drawing and ask whether it meets S5.6.1(e). The answer is no. The new version of the drawing consists of three figures that you believe constitute the symbol 'DOT.' Your new drawing continues to incorporate a corporate logo in lieu of the letter 'O.' As explained in our July 15, 1994 letter, because the symbol DOT constitutes the manufacturer's certification that the helmet conforms to Standard No. 218, there must be no ambiguity in the symbol. Using the corporate logo in lieu of the letter 'O' introduces ambiguity as to whether the manufacturer has certified the helmet. Thus, the new version of the drawing you provided does not meet S5.6.1(e) of Standard No. 218. I hope this answers your question. Sincerely, John Womack Acting Chief Counsel; |
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ID: aiam1920OpenMr. Andrew H. Swartz, Johnson, Hogan & Ometer, Post Office Drawer 668, Moneterey, CA 93940; Mr. Andrew H. Swartz Johnson Hogan & Ometer Post Office Drawer 668 Moneterey CA 93940; Dear Mr. Swartz: This is in response to your letter of April 11, 1975, requesting a interpretation of the meaning of 'gross vehicle weight rating.'; The gross vehicle weight rating (GVWR) of a trailer consists of th weight of the empty trailer plus its rated cargo load. The weight of the tractor is not included. The tractor and the trailer are considered as two separate vehicles, each with its own individual GVWR.; The Distributors Association interpretation you cited is correct, bu you appear to have misinterpreted it. In the case of a semi-trailer, a significant portion of the loaded trailer's GVWR may be supported by the tractor's rear axle. Therefore, the trailer's GVWR may be significantly higher than its gross axle weight rating, which is the weight an entire axle system, including tires, wheels, axle, and suspension systems, is capable of supporting.; Please let me know if you need further assistance. Yours truly, Richard B. Dyson, Assistant Chief Counsel |
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ID: aiam0632OpenMr. Harold E. Krause, Vice-President, Zecol Inc., P.O. Box 1100, Milwaukee, Wisconsin 53201; Mr. Harold E. Krause Vice-President Zecol Inc. P.O. Box 1100 Milwaukee Wisconsin 53201; Dear Mr. Krause: In response to your letter of February 28, I enclose a copy of Federa Motor Vehicle Safety Standard No. 116, *Motor Vehicle Brake Fluids*, which became effective March 1, 1972.; Paragraph S5.2 as amended specifies the appropriate labeling fo containers of fluid manufactured on or after March 1. If the labeled on containers in stock do not meet the new requirements, you may affix a conforming gummed label over them.; I recommend that you subscribe to the Federal Register ($25.00 pe year, from Superintendent of Documents, U.S. Government Printing Office, Washington, D.C. 20402). Which contains all Federal regulations as issued or proposed on a daily basis. As a manufacturer in a regulated industry. it is your responsibility to be completely familiar with all applicable regulations. The Superintendent of Documents can also provide you with a subscription service to Federal Motor Vehicle Safety Standards ($8.00 per year), updated as new regulations are issued.; Yours truly, Richard B. Dyson, Assistant Chief Counsel |
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ID: aiam4108OpenPeter M. Kopanon, Director, Vehicle Inspection Services, Massachusetts Registry of Motor Vehicles, 100 Nashua Street, Boston, MA 02114; Peter M. Kopanon Director Vehicle Inspection Services Massachusetts Registry of Motor Vehicles 100 Nashua Street Boston MA 02114; Dear Mr. Kopanon: This responds to your March 19, 1986 letter to our office concernin Federal preemption of state motor vehicle safety standards for school buses. Previously, you had requested us to clarify the language of section 103(d) of the National Traffic and Motor Vehicle Safety Act. We responded by letter dated March 24, 1986, which explained the phrase 'procured for the State's own use.' Your current letter focuses specifically on requirements for school bus mirrors in Federal Motor Vehicle Safety Standard No. 111, *Rearview Mirrors*, and asks whether Massachusetts could require an additional mirror on school buses owned by the state and its political subdivisions to enhance the view of school bus operator (sic).; The answer to your question is yes. As explained in our March 2 letter, under S103(d) of the Safety Act, a state may establish safety requirements for motor vehicles procured for its own use if such requirements impose the same or higher standard of performance than the Federal standard. The phrase 'higher standard of performance' means that the state standard must not conflict with the Federal standard, but may contain additional or more stringent requirements. Massachusetts may thus require an additional mirror on its school buses that provides greater views of areas in front of and along sides of the bus. This requirement, however, must not conflict with Federal requirements and prevent the school buses from complying with Federal safety standards.; We explained in our March 24 letter that states may not prescrib safety standards for privately-owned school buses transporting children to private and parochial schools that are not identical to the Federal safety standards covering the same aspects of performance. Your current letter asked further about Massachusetts' requirement that school committees (which we understand to be political subdivisions of the state) provide equal pupil transportation to public, private and parochial schools. You asked whether buses procured to fulfill this mandate are 'procured for the state's own use,' even though the buses would be used to transport students to private and parochial schools.; In our opinion, the answer is yes. NHTSA has interpreted the phras 'procured for its own use' to apply to any vehicle intended for transporting the public which is procured by a state or political subdivision thereof. Buses procured by the state to transport students to private and parochial schools are thus 'procured for the state's own use,' and may be required by Massachusetts to have additional mirrors to promote the safety of the school children they carry. We note, of course, that we suggest no position as to the constitutionality of state law.; I hope we have responded to your concerns. Please contact my office i you have further questions.; Sincerely, Erika Z. Jones, Chief Counsel |
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ID: aiam4488OpenKarl-Heinz Faber Vice President Product Compliance and Service Mercedes-Benz of North America, Inc. P.O. Box 350 Montvale, NJ 07645; Karl-Heinz Faber Vice President Product Compliance and Service Mercedes-Benz of North America Inc. P.O. Box 350 Montvale NJ 07645; "Dear Mr. Faber: Thank you for your letter concerning the requirement of Standard No. 210, Seat Belt Assembly Anchorages. In particular, you asked for an interpretation of the provisions of S4.3 of the standard. I regret the delay in answering your questions. S4.3 of Standard No. 210 provides, in part, that 'Anchorages for automatic and for dynamically tested seat belt assemblies that meet the frontal crash protection requirements of S5.1 of Standard No. 208 (49 CFR Part 571.208) are exempt from the location requirements of this section.' (Emphasis added.) You first asked the agency to confirm that anchorages to be used with automatic and dynamically tested safety belts that meet the requirements of S5.1 of Standard No. 208 are exempt from all of the anchorage location requirements of S4.3. You are correct that S4.3 of Standard No. 210 provides that such anchorages are exempt from all the location requirements. The amendment to exempt anchorages of dynamically tested seat belt assemblies from the anchorage location requirements of Standard No. 210 became effective on May 5, 1986, well in advance of the September 1, 1989 effective date for dynamic testing of manual belts. This effective date indicates that the agency did not intend to limit the exemption from the anchorage location requirements to manual safety belts that were required to be dynamically tested. Additionally, the exemption applies to dynamically tested seat belt assemblies that 'meet' the frontal crash protection requirements of Standard No. 208, rather than to vehicles 'subject to' the frontal crash protection requirements of that Standard. This language indicates that NHTSA intended to allow manufacturers to take advantage of the exemption from the anchorage location requirements for dynamically tested safety belts before the dynamic testing requirements were applicable to such belts. Accordingly, if a vehicle is equipped with a manual safety belt at either or both front outboard seating positions, and the anchorage or anchorages for those belts do not comply with the anchorage location requirements set forth in S4.3 of Standard No. 210, the manufacturer must certify that the belts attached at any such anchorage points comply with S5.1 of Standard No. 208. In your second question, you asked the following: We also understand that such dynamic testing may be combined with other compliance testing, and the vehicle or vehicles used may be equipped 'as delivered' for sale to a consumer. Accordingly, the vehicle structure with built-in energy management features, seats with designed-in anti-submarining construction, energy absorbing instrument panel, collapsible steering column, driver and/or passenger airbag(s), anti-lacerative windshield glass, emergency tensioning retractors, etc. may be installed and functional, where applicable, during the compliance crash test. During its compliance testing, NHTSA combines a test of the occupant crash protection capabilities of automatic or manual safety belts with testing done to determine compliance with other standards. The agency tests vehicles to the frontal barrier crash requirements of Standard Nos. 208, 212, 219, and 301 in a single barrier impact. In conducting these compliance tests, NHTSA tests vehicles in their 'as delivered' form with all items of standard equipment present in the vehicle. Thus, if a vehicle has devices, such as an air bag system or pre-tensioning devices for the belts, installed in the vehicle as items of standard equipment, NHTSA's compliance testing is conducted with those items in place and fully functioning. If our compliance testing shows that a vehicle tested with a manual safety belt at one or both front outboard seating positions complies with the occupant crash protection requirements of S5.1 of Standard No. 208, then the anchorages for the belt or belts would not be subject to the anchorage location requirements of S4.3 of Standard No. 210. If you have any further questions, please let me know. Sincerely, Erika Z. Jones Chief Counsel"; |
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ID: aiam4522OpenMr. Kent B. Robinson 18230 Kingsdale Ave., Apt. D Redondo Beach, CA 90278; Mr. Kent B. Robinson 18230 Kingsdale Ave. Apt. D Redondo Beach CA 90278; Dear Mr. Robinson: This is in reply to your letters of December 3 l987, January 19, 1988, and April 4, l988 (to Taylor Vinson of this Office), asking whether a device of your invention complies with all applicable Federal regulations. You have also requested information on how to petition for adoption of this device as mandated equipment on new motor vehicles. We regret the delay in responding to your letter. You have requested confidentiality of this matter to the extent permissible. As Mr. Donaldson of this Office explained to you by phone on January 14, our practice is to make available for public perusal copies of all agency interpretations, but not necessarily the correspondence that occasioned the interpretation, and, upon request, to delete from the interpretation the name and address and other data that might identify the person requesting the interpretation. You have assented to the withholding of your name and address in your letter of January 19. In that letter you requested withholding the drawings you enclosed on December 3. We shall not attach them to the copy of this letter made publicly available (although they will be subject to review by agency personnel who review this letter before I have signed it, and may be subject to eventual disclosure under a Freedom of Information Act request). However, the device must be described to the extent necessary to allow a reader to understand just what the opinion covers. Your device is a horizontal bar of lamps mounted inside the rear window of a passenger car consisting of the center highmounted stop lamp in the center, flanked by back up lamps, which are themselves flanked by left and right turn signal lamps. Each of the five lamps would have a lens area approximately 6' wide and 1 1/2 inches high. The applicable Federal law and regulation is the National Traffic and Motor Vehicle Safety Act and Federal Motor Vehicle Safety Standard No. 108 Lamps, Reflective Devices, and Associated Equipment. With respect to acceptability of your device as an item of original equipment, for purposes of this interpretation we assume that the device is intended to replace the standard center highmounted stoplamp, but only to supplement the backup and turn signal lamps. Your device appears permissible as an item of original equipment under Standard No. 108 provided that all requirements for the center highmounted stoplamp continue to be met. We call your specific attention to the fact that means must be provided to minimize reflections from the center lamp upon the rear window glazing that might be visible to the driver, either directly or indirectly in the rearview mirror. Supplementary original lighting equipment is permissible under Standard No. 108 as long as it does not impair the effectiveness of lighting equipment required by the standard. The certification by a manufacturer that its vehicle complies with Standard No. 108 would encompass a certification that there is no impairment by any supplemental lighting equipment. The vehicle manufacturer must also consider whether any device installed in a rear window affects compliance with the interior rearview mirror field of view requirements specified by Standard No. lll Rearview Mirrors, and if affirmative to provide a passenger side exterior mirror. The Vehicle Safety Act covers safety related defects as well as motor vehicle safety standards, requiring notification of purchasers and remedy of safety related defects when they occur. Spillage of light upon the rear glazing could be considered as a safety related defect, and, for this reason, means should be provided to minimize reflections upon the rear glazing from all lamps in the array, and not just the center lamp. The applicable Federal law for aftermarket equipment is also the Vehicle Safety Act. It prohibits modifications by manufacturers, distributors, dealers, and motor vehicle repair businesses to vehicles if those modifications render inoperative in whole or in part equipment installed in accordance with a safety standard. Center highmounted lamps have been required as original equipment on new cars manufactured on or after September l, l985. Because of the potential for interfering with the effectiveness of the center lamp, we would regard removal of an original equipment center lamp and substitution of your device including its center lamp as rendering the center lamp partially inoperative within the meaning of the prohibition. However, if the modification is such that it can be done by the vehicle owner, the Act does not prohibit an owner from it. Further, the Act would not prohibit in any way the installation of your device on passenger cars manufactured before September l, 1985. However, supplementary lighting devices sold in the aftermarket are regulated by each State in which the device would be sold and used. Although we are not conversant with those laws, you may consult the American Association of Motor Vehicle Administrators, 4600 Wilson Boulevard, Arlington, Va. 22203 for an opinion. You have also asked how this device could be mandated as original equipment on new passenger cars. Any interested person may petition the Administrator for an amendment of Standard No. 108. However, the Vehicle Safety Act requires the safety standards to be standards for motor vehicle performance, and, to the extent possible, the agency attempts to minimize standards expressed in terms of design. For the same reason, the agency does not normally propose adoption of proprietary designs. As one of the requirements of a petition for rulemaking is that it contain the name and address of the petitioner, it might not be possible to afford the same degree of confidentiality to a petition that it is to a request for an interpretation. Your letter of April 4 asks a slightly different question on the subject of what is allowed to be viewed by other motorists in or around the rear window, with specific reference to turn signals, backup lamps, and hazard warning signals. The relevant portions of Standard No. 108 are those relating to mounting height. The maximum mounting height of 83 inches allowed for turn signals (which commonly also serve as hazard warning signals) is unlikely to be exceeded by turn signals mounted in the rear window area. There is no maximum restriction on the mounting height of backup lamps but we do have performance criteria which must be met in order to ensure that they can satisfy their intended function of providing illumination behind the vehicle. Finally, you should realize that it is incorrect to refer to your device as a 'third tail light assembly.' A taillamp is a specific rear lamp required by Standard No. 108, and one which you have not incorporated into your assembly. I hope that this answers your questions. As you requested in a phone call to Taylor Vinson the other day, we are returning the originals of your correspondence. Sincerely, Erika Z. Jones Chief Counsel Enclosures; |
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ID: aiam1720OpenMr. J. Robert Horst, Corporate Attorney, Eaton Corporation, 100 Erieview Plaza, Cleveland, OH 44114; Mr. J. Robert Horst Corporate Attorney Eaton Corporation 100 Erieview Plaza Cleveland OH 44114; Dear Mr. Horst: This responds to your November 22, 1974, request for an interpretatio of language in Standard No. 121, *Air brake systems, that regulates electrical failure of the antilock systems which may be installed by vehicle manufacturers to meet the standard's performance requirements. You ask whether the S5.1.6 requirement for a continuous warning light 'in the event of total electrical failure' includes (1) any failure within the antilock system other than complete loss of all electrical power, or (2) any failure in the vehicle power source to the antilock components or from the antilock components to the signal lamp in the driver's compartment. You also ask whether the S5.5.1 requirement that 'electrical failure of any part of the antilock system shall not increase the actuation and release times of the service brakes' permits an increase in actuation time while the antilock logic circuity (sic) first recognizes a failure that occurs during brake actuation and then deactivates the antilock system.; In responding to a similar request for interpretation on the meaning o 'total electrical failure' we interpreted this phrase in a May 26, 1972, letter to Wagner Electric to mean any electrical failure within the antilock electrical system circuitry which would cause loss of antilock control of every wheel on the vehicle. This requires that the signal activate when complete loss of electrical power is sensed within the antilock system. We understand that many available systems also signal partial loss of electrical integrity, and we may give future consideration to a requirement that the signal activate in response to specific 'partial failures.'; With regard to failures in the battery or in the wiring from th battery to the antilock or from the antilock to the signal in the driver's compartment, we cannot state that a failure in these systems would not be non-compliance with S5.1.6. Our other standards (e.g., *Lamps, reflective devices, and associated equipment) assume and require the integrity of the wiring systems necessary to meet the requirement. Of course an isolated case of battery failure or a broken wire to the signal lamp would not in itself be considered a non-compliance. It would appear that a manufacturer of antilock systems is not in a position to certify that the signal generated by his product will reach the dashboard.; You pointed out that, with regard to S5.5.1's requirement tha 'electrical failure of any part of the antilock system shall not increase the actuation and release times of the service brakes,' the possibility exists of an antilock electrical failure occurring during a brake application which would necessitate a period for recognition of the failure and deactivation of the system. This recognition period would increase the actuation time. The NHTSA believes that this period of initial recognition is desirable to detect and eliminate incorrect indications of malfunction without interfering with the antilock function. Until the wording of this section is modified to reflect this exception, the NHTSA interprets S5.5.1 to permit an increase in actuation time while antilock logic circuitry first recognizes a failure occuring (sic) during brake actuation, and deactivates the antilock system.; Yours truly, Richard B. Dyson, Acting Chief Counsel |
Request an Interpretation
You may email your request to Interpretations.NHTSA@dot.gov or send your request in hard copy to:
The Chief Counsel
National Highway Traffic Safety Administration, W41-326
U.S. Department of Transportation
1200 New Jersey Avenue SE
Washington, DC 20590
If you want to talk to someone at NHTSA about what a request for interpretation should include, call the Office of the Chief Counsel at 202-366-2992.
Please note that NHTSA’s response will be made available in this online database, and that the incoming interpretation request may also be made publicly available.