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
| Interpretations | Date |
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ID: 3243yyOpen Mr. Don Weidman Dear Mr. Weidman: This responds to your letter of November 25, 1991, with respect to the applicability of some new requirements of Motor Vehicle Safety Standard No. 108 to "agricultural vehicles and implements when they are traveling on the highways." Specifically you ask whether the requirements of Standard No. 108 or SAE J137 must be complied with when agricultural equipment is in use. The Federal motor vehicle safety standards apply to motor vehicles, which are defined, in pertinent part, by the National Traffic and Motor Vehicle Safety Act as vehicles "manufactured primarily for use on the public streets, roads, and highways." Because the primary use for agricultural vehicles such as farm tractors, combines, and the like is off the public roads, and their use of the public roads is incidental to their intended use, NHTSA does not consider agricultural vehicles to be "motor vehicles" within the meaning of the Act. This means that they do not have to conform to Standard No. l08, or any other Federal motor vehicle safety standard. Regulations governing the use of the public roads are issued and enforced by the individual States. We have no knowledge whether any State requires the lighting on agricultural equipment to conform to SAE J137, or to Standard No. l08. The American Association of Motor Vehicle Administrators, 4600 Wilson Boulevard, Arlington, Va. 22203, may be able to answer this question for you. Sincerely,
Paul Jackson Rice Chief Counsel /ref:l08 d:l2/l0/9l |
1970 |
ID: nht94-8.48OpenDATE: January 21, 1994 FROM: John Womack -- Acting Chief Counsel, NHTSA TO: Kathy Rose -- Account Directive, FitzGerald Corporation TITLE: None ATTACHMT: Attached to letter dated 10/12/93 from Kathy Rose to Glen Beck (OCC 9528) TEXT: Your letter of October 12, 1993, to the office of Motor Carriers in Sacramento, has reached us for reply. Your company produces a "trailer skirting" for van trailers, and some of your customers have asked "whether it is legal to have the retroreflective tape (which is required by Motor Vehicle Safety Standard No. 108) to be applied to the length of the trailer be placed below the trailer, on the trailer skirting." The letter does not indicate whether the skirting is intended as original or aftermarket equipment. If the skirting is original equipment that is added to the trailer at the time of its manufacture and intended to remain there for the life of the trailer, the conspicuity treatment required by the standard may be affixed to it, provided that it is mounted as near as practicable within a range that is not less than 375mm and not more than 1525mm (approximately 15 to 60 inches) above the road surface. Under that condition, the portion of the trailer side that is above the skirting need not be equipped with the conspicuity treatment. If the skirting is aftermarket equipment, there is no requirement or restriction relating to conspicuity treatment of the skirting. We assume that the trailer to which it will be attached, if manufactured on or after December 1, 1993, will bear conspicuity markings in accordance with the standard. |
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ID: nht91-7.41OpenDATE: December 10, 1991 FROM: Paul Jackson Rice -- Chief Counsel, NHTSA; Signature by Kenneth Weinstein TO: Don Weidman -- Manager, Special Projects, The Grote Manufacturing Company TITLE: None ATTACHMT: Attached to letter dated 11-25-91 from Don Weidman to Paul Jackson Rice (OCC 6709) TEXT: This responds to your letter of November 25, 1991, with respect to the applicability of some new requirements of Motor Vehicle Safety Standard No. 108 to "agricultural vehicles and implements when they are traveling on the highways." Specifically you ask whether the requirements of Standard No. 108 or SAE J137 must be complied with when agricultural equipment is in use. The Federal motor vehicle safety standards apply to motor vehicles, which are defined, in pertinent part, by the National Traffic and Motor Vehicle Safety Act as vehicles "manufactured primarily for use on the public streets, roads, and highways." Because the primary use for agricultural vehicles such as farm tractors, combines, and the like is off the public roads, and their use of the public roads is incidental to their intended use, NHTSA does not consider agricultural vehicles to be "motor vehicles" within the meaning of the Act. This means that they do not have to conform to Standard No. 108, or any other Federal motor vehicle safety standard. Regulations governing the use of the public roads are issued and enforced by the individual States. We have no knowledge whether any State requires the lighting on agricultural equipment to conform to SAE J137, or to Standard No. 108. The American Association of Motor Vehicle Administrators, 4600 Wilson Boulevard, Arlington, Va. 22203, may be able to answer this question for you.
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ID: nht90-1.31OpenTYPE: INTERPRETATION-NHTSA DATE: 01/30/90 FROM: TILMAN SPINGLER -- ROBERT BOSCH GMBH TO: RICHARD VAN IDERSTINE -- OFFICE OF RULEMAKING, NHTSA TITLE: TELEFAX ATTACHMT: ATTACHED TO LETTER DATED 3-23-90 TO TILMAN SPINGLER, ROBERT BOSCH GMBH, FROM STEPHEN P. WOOD, NHTSA; [REDBOOK A35; INTERP. STD. 108]; ALSO ATTACHED TO LETTER TO TAYLOR FROM RICH VAN IDERSTINE DATED 2-13-90; [43880] TEXT: For some future projects I ask you to answer the following questions 1) To turn the adjusting screws of a HB2-headlamp it will be necessary to remove two snap on covers without the use of any tool. Will this be legal? 2) A combination of HB2-headlight (low- + high-beam) and auxiliary driving beam in one unit shall be equipped with only vertical adjusting screws for the driving beam. The beampattern will be so wide, that even bulbs with extreme tolerances will allow t o meet all photometric requirements without horizontal adjustment. Will this be legal? 3) When will the 9007 bulb be legal? Date of final rule? Thanks for a quick answer |
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ID: nht93-7.9OpenDATE: October 5, 1993 FROM: John Womack -- Acting Chief Counsel, NHTSA TO: Anonymous TITLE: None ATTACHMT: Attached to letter dated 9/9/93 from Anonymous to John Womack (Part 541) TEXT: This responds to your request for an interpretation of the theft prevention standard (49 CFR Part 541). You asked whether "embossing" is permitted to mark engines and transmissions for original and replacement parts. You also asked whether the symbol "DOT" and your company's logo may appear in identical locations on original and replacement parts. As explained below, embossing is permitted, but "DOT" may not appear on original parts. The relevant Part 541 provisions are Sections 541.5 Requirements for passenger cars and 541.6 Requirements for replacement parts. Section 541.5(a) states that each passenger car subject to the theft prevention standard must have an identifying number "affixed or inscribed" on each of fourteen specified original parts. Section 541.6(a) states that each replacement part must have the trademark of the replacement part manufacturer and the letter "R" "affixed or inscribed" on such replacement part. Section 541.6(f) states that each replacement part must bear the symbol "DOT," that is "inscribed or affixed." In response to your first question about embossing, we note the required information on original and replacement parts must be "inscribed or affixed." To determine whether embossing is a means of "inscribing," we have reviewed the dictionary's definition. "Inscribe" means "to mark or engrave (words, symbols, etc.) on some surface." (See Webster's New World Dictionary, College Edition.) Since embossing is a means of marking on a surface, embossing would be included within the definition of "inscribing." The preamble to the final rule that established Part 541 confirms the above interpretation. NHTSA then stated that it "has no authority to mandate the use of any particular marking system. NHTSA has authority only to establish performance criteria that will accomplish the purposes of the Theft Act. The manufacturers are free to select any marking system that satisfies those criteria." (See 50 FR 43166, at 431701; October 24, 1985.) Thus, if your company believes embossing satisfies Part 541 performance criteria, it may emboss. Your second question asked whether "DOT" may be marked on original parts, The answer is no. Original parts must be marked with the vehicle identification number. If an original part includes "DOT," the part would be dual marked. "Dual marking" was discussed in Part 541's preamble: ... the agency cannot allow such dual markings under the theft prevention standard. Dual markings would give thieves the opportunity to present stolen original equipment parts as properly marked replacement parts. ... This would not serve the purpose of the Theft Act of "decreasing the ease with which certain stolen vehicles and their major parts can be fenced." (See 50 FR 43166, at 43179). It would also be inappropriate to mark "DOT" on an original part because "DOT" is a manufacturer's certification that a replacement part conforms to Part 541. (See 49 CFR 541.6(f)). Since an original part would not conform to Part 541's requirements for replacement parts, it would be inappropriate for a manufacturer to certify compliance by placing "DOT" on the original part. Finally, it was requested that your company not be identified in public copies of this letter, and that your incoming letter be purged of references to your company. In order to save time, we agree to do this. In the future, however, please note that 49 CFR Part 512 Confidential Business Information sets forth procedures for protecting information that your company believes is confidential. I hope this satisfactorily responds to your concerns. If there are further questions, please contact Dorothy Nakama of my staff at (202) 366-2992. |
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ID: 9067Open Dear : This responds to your request for an interpretation of the theft prevention standard (49 CFR Part 541). You asked whether "embossing" is permitted to mark engines and transmissions for original and replacement parts. You also asked whether the symbol "DOT" and your company's logo may appear in identical locations on original and replacement parts. As explained below, embossing is permitted, but "DOT" may not appear on original parts. The relevant Part 541 provisions are Sections 541.5 Requirements for passenger cars and 541.6 Requirements for replacement parts. Section 541.5(a) states that each passenger car subject to the theft prevention standard must have an identifying number "affixed or inscribed" on each of fourteen specified original parts. Section 541.6(a) states that each replacement part must have the trademark of the replacement part manufacturer and the letter "R" "affixed or inscribed" on such replacement part. Section 541.6(f) states that each replacement part must bear the symbol "DOT," that is "inscribed or affixed." In response to your first question about embossing, we note the required information on original and replacement parts must be "inscribed or affixed." To determine whether embossing is a means of "inscribing," we have reviewed the dictionary's definition. "Inscribe" means "to mark or engrave (words, symbols, etc.) on some surface." (See Webster's New World Dictionary, College Edition.) Since embossing is a means of marking on a surface, embossing would be included within the definition of "inscribing." The preamble to the final rule that established Part 541 confirms the above interpretation. NHTSA then stated that it "has no authority to mandate the use of any particular marking system. NHTSA has authority only to establish performance criteria that will accomplish the purposes of the Theft Act. The manufacturers are free to select any marking system that satisfies those criteria." (See 50 FR 43166, at 43170; October 24, 1985.) Thus, if your company believes embossing satisfies Part 541 performance criteria, it may emboss. Your second question asked whether "DOT" may be marked on original parts. The answer is no. Original parts must be marked with the vehicle identification number. If an original part includes "DOT," the part would be dual marked. "Dual marking" was discussed in Part 541's preamble: ... the agency cannot allow such dual markings under the theft prevention standard. Dual markings would give thieves the opportunity to present stolen original equipment parts as properly marked replacement parts. ... This would not serve the purpose of the Theft Act of "decreasing the ease with which certain stolen vehicles and their major parts can be fenced." (See 50 FR 43166, at 43179). It would also be inappropriate to mark "DOT" on an original part because "DOT" is a manufacturer's certification that a replacement part conforms to Part 541. (See 49 CFR 541.6(f)). Since an original part would not conform to Part 541's requirements for replacement parts, it would be inappropriate for a manufacturer to certify compliance by placing "DOT" on the original part. Finally, it was requested that your company not be identified in public copies of this letter, and that your incoming letter be purged of references to your company. In order to save time, we agree to do this. In the future, however, please note that 49 CFR Part 512 Confidential Business Information sets forth procedures for protecting information that your company believes is confidential. I hope this satisfactorily responds to your concerns. If there are further questions, please contact Dorothy Nakama of my staff at (202) 366-2992. Sincerely,
John Womack Acting Chief Counsel ref:541 d:10/5/93 |
1993 |
ID: Labelpermanency_6507OpenMr. Randy Kiser Dear Mr. Kiser: This responds to your letter in which you requested clarification of the permanency requirement for labels under Federal Motor Vehicle Safety Standard (FMVSS) No. 213, Child restraint systems. As explained below, we would consider "permanent" a label conforming to the requirements you described in your letter and remaining legible for the life of the child restraint system (CRS) to which it is attached. In your letter, you stated that your company believes that permanency definitions provided by the American Society for Testing Materials (ASTM), when taken together with previous interpretations provided by the National Highway Traffic Safety Administration (NHTSA), provide an appropriate definition for label permanency, as it applies to a CRS. The ASTM standard for CRSs provides that a label, excluding a label attached by a seam, is permanent if, during an attempt to remove it: (1) the label cannot be removed without the aid of tools or solvents; (2) if it is a paper label, it tears into pieces; or (3) such action damages the surface to which it is attached. [1] Your letter also cited language from the Notice of Proposed Rulemaking for 49 CFR Part 541, Motor Vehicle Theft Prevention Standards, in which the agency stated that the removal of a label must "create a 'footprint' (i.e., physical evidence that an affixation was originally present or required to be present) on that part." [2] S5.5.1 of FMVSS No. 213 requires that each CRS be permanently labeled with specified information, including information on proper use. A CRS may not protect a child in a crash if the CRS is not properly installed or the child is not properly secured. The label provides a constant reminder on how to correctly use the restraint. [3] However, a label cannot be effective if it does not remain affixed to the restraint or cannot be read. Label permanency is particularly important for subsequent owners of a restraint, who may not have access to the original instructions. Further, the model and manufacturer information must remain legible in order to identify a restraint that is the subject of a recall. For a label to be permanent, it must remain affixed and legible under normal conditions for the life of the restraint to which it is attached. If a label used by your company were to meet the ASTM and agency criteria you outlined in your letter and listed above, and remain legible for the life of the restraint, we would deem it permanently attached. Note two caveats, however. Labels should not be attached in a manner that invites their removal. In a June 26, 1997, letter to Mr. Strawn Cathcart, we stated that an air bag warning label could not be sewn on only one side into a seam. We determined that, by virtue of the location of the label (where an infants head would be located) and ease of detachment by cutting, tearing or pulling off a single row of stitching, the sewn-in label invited removal. As such, we concluded that the label was unlikely to stay attached during the lifetime of the child restraint in satisfaction of the permanently affixed requirement of FMVSS No. 213. Second, the durability of labels is evaluated under NHTSAs Ease of Use CRS rating program. If a label is already peeling when the new CRS is removed from the packaging material at the test lab, the CRS will receive a lower score on the durability of its label than a CRS whose label is not peeling. I hope this information is helpful. If you have any further questions, please contact Mr. Chris Calamita of my staff at (202) 366-2992. Sincerely, Jacqueline Glassman Ref.213 [1] See, ASTM F 833 00, Standard Consumer Safety Performance Specification for Carriages and Strollers, Sections 7.8.1 and 7.8.2. [2] 50 Federal Register 19728, 19731; May 10, 1985. [3] 44 FR 72131, 72316; December 13, 1979. |
2003 |
ID: 07-004380-3asOpenDietmar K. Leicht Secretary General Federation of European Manufacturers of Friction Materials Robert-Perthel-Str. 49 D-50739 Kln Germany Dear Mr. Leicht: This responds to your letter in which you ask whether AMECA Standard VESC V-3 is still a legal requirement and mandatory in [the U.S.]. You stated that your members would like to know which legal requirements must be fulfilled for the export of brake linings to the United States. You cited brake linings for the aftermarket which are approved in Europe by ECE Regulation No. 90 and OE brake linings offered on the market as original replacement parts which are approved in Europe by ECE Regulation No. 13 (13H). By way of background, the National Highway Traffic Safety Administration (NHTSA) is authorized under 49 U.S.C. Chapter 301 to issue Federal motor vehicle safety standards applicable to new motor vehicles and items of motor vehicle equipment. NHTSA does not approve motor vehicles or motor vehicle equipment, nor do we endorse any commercial products. Instead, our statute establishes a self-certification process under which each manufacturer is responsible for certifying that its products meet all applicable safety standards. The agency periodically tests vehicles and equipment items for compliance with the standards, and also investigates reports of safety-related defects. There is currently no Federal motor vehicle safety standard for new or replacement linings used on motor vehicles sold in the United States. However, new vehicles are required to be certified to brake safety standards which specify minimum performance requirements under a variety of different test conditions. While the brake linings used on a vehicle could affect the vehicles ability to meet some of the minimum performance requirements, the requirements do not establish any separate performance requirements for the brake linings. The Federal requirements operate separately from the State law requirements. States are free to impose their own requirements on motor vehicles and motor vehicle equipment, unless such requirements are preempted by Federal law. We are unable to provide information about possible State requirements for brake linings. Standard V-3 was promulgated by the Vehicle Equipment Safety Commission (VESC), and specified minimum requirements and uniform test procedures for motor vehicle brake linings. VESC ceased operations in January 1984. With regard to Federal law, the VESC V-3 standard is not and never was a legal requirement. However, we cannot provide information as to whether some or all of the requirements of this standard may have been adopted as State laws. In your letter, you referenced AMECA. We note that, according to its website, the Automotive Manufacturers Equipment Compliance Agency, Inc. (AMECA) was incorporated in late 1994 to continue providing the same safety equipment services to the states that the American Association of Motor Vehicle Administrators had provided since 1967. Finally, brake linings are items of "motor vehicle equipment" and are subject to the notification and remedy (recall) provisions of 49 U.S.C. 30118-30120. If a manufacturer or NHTSA determines that the product contains a safety-related defect, the manufacturer is responsible for notifying purchasers of the defective vehicle or item of motor vehicle equipment and remedying the problem free of charge. (This "recall" responsibility is borne by the vehicle manufacturer in cases in which the equipment is installed on a new vehicle by or with the express authorization of that vehicle manufacturer.) I am enclosing an information sheet we prepared for new manufacturers of motor vehicles and motor vehicle equipment that provides additional information about relevant Federal states and NHTSA standards and regulations affecting motor vehicle and motor vehicle manufacturers. We hope this information has been helpful. If you have any further questions, you may call Ari Scott of my staff at (202) 366-2992. Sincerely yours, Anthony M. Cooke Chief Counsel Enclosure ref:VSA d.11/20/08 |
2008 |
ID: nht91-7.20OpenDATE: 11/26/91 FROM: KATHLEEN DEMETER -- ASSISTANT CHIEF COUNSEL FOR GENERAL LAW, NHTSA TO: RICHARD LANGLAIS -- ENGINEER, PRELCO INC. TITLE: NONE ATTACHMT: ATTACHED TO LETTER DATED 12-7-92 FROM RICHARD LANGLAIS TO MARVIN SHAW (OCC 8067); ALSO ATTACHED TO LETTER DATED 2-23-93 FROM JOHN WOMACK TO RICHARD LANGLAIS (A40; STD. 205; PART S51) TEXT: This is in response to your recent letter which requested information on obtaining a DOT number. Before your company can begin importing automotive products into this country and prior to the assignment of a DOT identification number, you must provide an original letter of designation and acceptance by the designated party that complies with the provisions of 49 CFR @ 551.45. The required designation should be mailed to the Office of Chief Counsel, National Highway Traffic Safety Administration, Room 5219, 400 Seventh Street, SW, Washington, DC 20590, and must include the following information: 1. A certification that the designation is valid in form and binding on the manufacturer under the laws, corporate by-laws, or other requirements governing the making of the designation at the time and place where it is made; 2. The full legal name, principal place of business, and mailing address of the manufacturer; 3. Marks, trade names, or other designations of origin of any of the manufacturer's products which do not bear its name; 4. A statement that the designation shall remain in effect until withdrawn or replaced by the manufacturer; 5. A declaration of acceptance duly signed by the agent appointed, which must be a permanent resident of the United States and may be an individual, a firm, or a U.S. corporation; 6. The full legal name and address of the designated agent; and 7. The signature of one with authority to appoint the agent. The signer's name and title should be clearly indicated beneath the signature. I have enclosed a copy of 49 CFR @ 551.45, and a sample of a properly executed designation of agent. If you have any questions about the requirements for the appointment of an agent, please do not hesitate to contact me. For you information, I have also enclosed a handout which provides additional information for new manufacturers of motor vehicles and motor vehicle equipment and a copy of federal regulations relevant to automotive glazing. If you have any questions concerning this information, please contact Mr. Clarke Harper, National Highway Traffic Safety Administration, Office of Vehicle Safety Standards, Room 5320, 400 Seventh Street, S.W., Washington, D.C. 20590. |
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ID: 11188Open Mr. Larry W. Strawhorn Dear Mr. Strawhorn: This letter responds to your request for an interpretation of the antilock power circuit requirements set forth at S5.1.6.3 of Standard No. 121, Air Brake Systems. This provision states that S5.1.6.3 Antilock Power Circuit for Towed Vehicles. Each truck tractor manufactured on or after March 1, 1997 and each single unit vehicle manufactured on or after March 1, 1998 that is equipped to tow another air-braked vehicle shall be equipped with one or more separate electrical circuits, specifically provided to power the antilock system on the towed vehicle(s). Such a circuit shall be adequate to enable the antilock system on each towed vehicle to be fully operable. (Emphasis added.) You believe that the phrase "separate electrical circuit" allows for the continued use of the single SAE J560 connector if one of the seven pins provides full-time power for the ABS. You further believe that the ABS malfunction signal can be multiplexed on any circuit of the connector and that the other trailer devices can be powered off the circuit as long as the circuit is adequate to enable the antilock system on each towed vehicle to be fully operable. In the March 10, 1995 final rule, NHTSA decided to adopt the proposed full-time power requirement for trailer ABSs. (60 FR 13216) The agency explained that it amended the standard's wording to clarify that towing vehicles must have a corresponding separate circuit specifically provided to power the antilock system on the towed vehicle or vehicles. The agency stated that requiring a separate circuit "will ensure the strongest possible source of electrical power from the tractor to ensure the functioning of all the ECUs and modulators that are employed in the antilock brake system, or systems, on single trailers, or multiple trailers and converter dollies in multi-trailer combinations.@ It also stated that this requirement will ensure a continuous malfunction indication whenever a malfunction exists. The agency further stated that it has left the decision about which type of connector should be used to the industry. In response to your question about the use of one of the pins in the seven-pin connector to provide full-time power for the ABS, the use of such a pin would be permissible provided that the pin services a "separate" electrical circuit to "specifically provide" full time power for the trailers in combination vehicles. This means that the circuit's sole function must be to provide ABS powering, i.e., other trailer devices may not be powered off this separate electrical circuit. This would preclude the use of the pin to power the ABS malfunction signal. Since the requirement for the ABS malfunction circuit did not specify that the circuit used for transmitting the malfunction signal be a "separate" one, ABS malfunction signals can be multiplexed on other circuits with pins in the electrical connector, but not on the circuit and pins used to power the ABS system. It is important to note that the ABS semitrailer fleet study report (DOT HS 808 059) concluded that the voltages delivered by powering system approaches that employed dedicated separate circuits (i.e., the Cole Hersee, ISO, and 6-pin auxiliary systems) were well within the required limits for ECU powering; whereas, the voltages delivered through the stoplamp circuit did not perform as well. The agency concluded that these data indicate the superiority of a separate circuit powering of the trailer ABS and therefore, justify the separate circuit requirement. As you are aware, NHTSA received several petitions for reconsideration about the separate electrical circuit. The agency anticipates that the final rule in response to these petitions for reconsideration will have a detailed discussion of these requirements. In addition, the agency may decide to modify these requirements. I hope this information has been helpful. If you have any other questions, please contact Marvin Shaw of my staff at this address or by phone at (202) 366-2992. Sincerely,
Samuel J. Dubbin Chief Counsel ref:121 d:11/17/95
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1995 |
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.