ID: 9252

Mr. James Schaub
Midas Muffler Shop
180 Gause Blvd.
Slidell, LA 70458

Dear Mr. Schaub:

This responds to your letter asking us about Federal Motor Vehicle Safety Standard No. 105 with regard to replacing brake rotors and/or drums. I apologize for the delay in our response. You stated that local automobile dealership service departments do not follow manufacturers' recommendations in this area, causing your customers to believe that your shop is fraudulently selling and installing parts on vehicles when they are not needed. You requested an interpretation of Standard No. 105 in this regard, and asked whether there is any basis for fraud in replacing rotors and drums when they are outside manufacturer safety tolerances. You stated that if you can present an established standard to your customers, you can prevent them from believing they have been taken advantage of.

By way of background information, the National Traffic and Motor Safety Act (Safety Act) authorizes the National Highway Traffic Safety Administration (NHTSA) to issue Federal motor vehicle safety standards for new motor vehicles and new motor vehicle equipment. Standard No. 105, Hydraulic Brake Systems, specifies requirements for hydraulic brake systems and associated parking brake systems. The standard applies to new motor vehicles.

While you asked for an interpretation of Standard No. 105, that standard is of little relevance to your situation. This is because the Federal motor vehicle safety standards do not apply to a motor vehicle after its first sale to a consumer. The Safety Act does include some provisions which are relevant to used vehicles. In particular, the Safety Act prohibits manufacturers, distributors, dealers, and motor vehicle repair businesses from knowingly rendering inoperative any safety device or element of design installed on or in a motor vehicle or item of motor vehicle equipment in compliance with a safety standard. However, this provision would ordinarily not be relevant to a decision whether to replace, or mill or turn, worn brake drums and rotors.

With respect to your desire to show your customers an established standard in this area, I can call your attention to NHTSA's vehicle in use inspection standards. These standards set forth criteria for, among other things, inspecting service brake systems. You should be aware that these standards were developed for use by the States in establishing their inspection requirements. Thus, the standards only apply to the extent that they are adopted by individual States. I have enclosed a copy of the standards for your information and particularly call your attention to section 570.5(f). That section, which applies to vehicles with a GVWR of 10,000 pounds or less, reads as follows:

(f) Disc and drum condition. If the drum is embossed with a maximum safe diameter dimension or the rotor is embossed with a minimum safety thickness dimension, the drum or disc shall be within the appropriate specifications. . . .

This section reflects the importance NHTSA places on following manufacturer recommendations in this area.

The states may regulate the repair of motor vehicles. We suggest that you investigate the laws of Louisiana to see whether they affect your situation.

We cannot advise you about Federal or state requirements concerning fraud. You may wish to contact the Federal Trade Commission, your state government, and/or a private attorney about this matter.

Sincerely,

John Womack Acting Chief Counsel

Enclosure

ref:105#570 d:5/18/94

ID: nht71-5.34

DATE: 12/29/71

FROM: AUTHOR UNAVAILABLE; L. R. Schneider; NHTSA

TO: National Committee on Uniform Traffic Laws and Ordinances

TITLE: FMVSS INTERPRETATION

TEXT: This is in response to your letter of March 3, 1971, concerning the preemption of State vehicle safety standards under section 103(d) of the National Traffic and Motor Vehicle Safety Act, 15 U.S.C. 1592(d). We apologize for the oversight that resulted in not answering the letter until this date.

You asked whether State laws requiring that vehicles having two red tail lamps, mounted on the same level and as widely spaced laterally as practicable, are preempted by Motor Vehicle Safety Standard No. 108. In our opinion the answer is no. Standard 108 has many detailed requirements that go beyond those described. Among them, however, are requirements that are substantively identical to your example, though not stated in precisely the same words. We do not interpret section 103(d), which prohibits a State standard "which is not identical to the Federal standard," as requiring the State requirement to be a verbatin copy of its Federal counterparts substantive identity of requirements is sufficient. Also, we do not interpret the statute as requiring the State to adopt all the Federal requirements on a given aspect of performance. It is sufficient that there be a Federal requirement that is substantively identical to the State requirement in question.

You also asked about two other requirements, as to which the answer may depend on a more detailed examination of their purposes and the circumstances under which they are enacted. One was the requirement that the light from the tail lamps be visible from a distance of 1,000 feet to the rear; the other was that a vehicle have "at least one tail lamp."

The guiding principle that we would apply to this situation is that State requirements that regulate the design of motor vehicles must be identical to the Federal standards, with the qualifications stated above. It was clearly the intent of Congress to provide for uniformity of regulation of the manufacturers in areas where the Federal agency has acted, and they did so by the identity requirement of section 103(d). By contrast, State requirements concerning the condition or adjustment of vehicles generally do not affect the requirements placed on manufacturers, and therefore do not fall within the section 103(d) identity provisions.

Applying this principle to your question, if the visibility requirement is construed by the State, and reasonably appears, to be basically a quantitatively stated requirement that the tail lamps be in good working order and not nearly degraded by conditions encountered in use, we would consider the requirement not to be preempted by section 103(d). Similarly, if the one tail lamp requirement is essentially a statement of required minimum working condition (as it appears to be on its face), it would not be preempted.

The issue you mentioned concerning the preemption of State laws applicable to vehicles in use was dealt with in detail in(Illegible Word). Tens' letter to you of December 21, 1970. As stated in that letter, our position is that the preemption question does not turn on whether the State law applies to pre-sale or on-the-road vehicles, and we feel that this position was upheld by the clear and compelling implication of the Super Lite cases. In light of the interpretations set forth in this letter, however, we do not believe that the problems of State law and enforcement that you felt may arise will be realized.

ID: nht71-5.57

DATE: 05/12/71

FROM: AUTHOR UNAVAILABLE; Robert L. Carter; NHTSA

TO: Mercedes-Benz of North America, Inc.

TITLE: FMVSS INTERPRETATION

TEXT: Thank you for your letter of April 20, 1971, regarding an interpretation for seat belt assemblies required by Federal Motor Vehicle Safety Standard No. 208 - Occupant Crash Protection.

It is our intent that an integral (3-point) lap and shoulder belt system, with a sliding attachment, could meet the requirements of the subject standard. Since paragraph S7.1.1 requires automatic adjustment by means of an emergency-locking retractor for this type of integral system (see S7.1.1.3), the sliding attachment friction could not unduly restrict adjusting movements of the belt, however, a nominal friction is permissible and is expected.

The seat belt assembly which you submitted to Mr. Clue Ferguson's Office of Crash Worthiness has been placed in Docket 69-7. This system would appear to have a nominal friction at the sliding adjustment, however, an actual vehicle installation is necessary to enable a full evaluation.

MERCEDES-BENZ OF NORTH AMERICA, INC.

April 20, 1971

Doug W. Toms, Director National Traffic and Highway Safety Administration

Subject: Seat Belt Assemblies According to FMVSS 208

The Motor Vehicle Safety Standard 208 which will be effective January 1, 1972, requires that seat belt assemblies shall adjust to fit the occupant by means of an automatic or emergency locking retractor. The seat belt assembly being considered for installation in our vehicles has been designed to comply with the subject Safety Standard. We would, however, appreciate receiving your confirmation that the design complies with the aspect of performance described in S7.1.1 of the Standard prior to equipping our vehicles.

The subject assembly consists of a single piece of webbing permanently attached at the outboard floor anchorage, with the release/fastening mechanism at the inboard anchorage forming the pelvic restraining loop and a third anchorage behind the shoulder forming the upper torso restraint. The webbing is fed during extension by an emergency locking retractor through the upper shoulder restraint anchorage to provide freedom of movement for the occupant.

Application of this assembly around the occupant is achieved by pulling the "tongue" portion of the attachment hardware from its fully retracted position at the "3" pillar, across the occupant down to the fixed buckle or receptable at the inboard anchorage. The webbing passes loosely through a slot in the tongue to provide a sliding adjustment during this application.

We are requesting your confirmation that this sliding adjustment specifically, will not be considered in non-compliance with your requirement for adjustment by the retractor because of the small amount of friction occuring at the webbing and tongue. It is our opinion that the friction is adequately overcome by the retractor force to provide proper adjustment. Additionally, the assembly when extended for use, will be drawn across the occupant, thus a snug fit across the pelvic region will be provided upon application thereby minimizing the need for further automatic adjustment by the retractor.

A sample of an assembly incorporating this design has been left at Mr. C. Ferguson's office for further evaluation by your staff. Upon receipt of your evaluation of this design we will advise our parent company accordingly.

H. W. Gerth General Manager Product Engineering and Service

cc: Mr. Wilfert Dr. Reidelbach

ID: GF006498

Mr. Jack W. DeYoung
Tumbleweed Trucks, Inc.
318 Kwanzan Drive
Lynden, WA 98264

Dear Mr. DeYoung:

This responds to your facsimile dated August 29, 2003, seeking further clarification of our interpretation letter sent to you on August 7, 2003. In response to our August 7^th letter, you have reprogrammed the flash rate in your hazard warning signal flasher. You now ask whether the newly reprogrammed flash rate complies with the requirements of Federal Motor Vehicle Safety Standard No. 108 (Standard No. 108).

By way of background, the National Highway Traffic Safety Administration (NHTSA) does not provide approvals of motor vehicles or motor vehicle equipment. Under 49 U.S.C. Chapter 301, manufacturers are required to certify that their vehicles and equipment meet applicable requirements.

As previously discussed, SAE Recommended Practice J945, "Vehicular Hazard Warning Signal Flasher," February 1966 (SAE 945), is incorporated by reference in Standard No. 108, as the Federal Requirement for Flashers. Paragraph 3 of J945 and its accompanying Figure 1 specify requirements for "Flash Rate and Percent Current On Time." The flash rate must be 60 to 120 flashes per minute for "normally open" (i.e., variable load) flashers, and 90 to 120 flashes per minute for "normally closed" (i.e., fixed load) flashers. This paragraph also specifies that:

"flashing rate . . . shall be measured after the flashers have been operating for a minimum of five consecutive cycles and shall be an average of at least three consecutive cycles." (emphasis added)

Your newly reprogrammed flash pattern operates as follows (in milliseconds):

ON	OFF	ON	OFF	ON	OFF
200	250	200	250	200	850

Our calculations indicate that the above flash pattern, taking into account the averaging procedure set forth in J945, is within the specified flash rate.

In considering this issue further, however, we believe this type of flash pattern is very different from what NHTSA contemplated in incorporating J945 by reference in Standard No. 108. As you know, existing flashers operate at an essentially constant rate. Moreover, while Figure 1 of J945 permits considerable flexibility in flash rate, our calculations indicate that the flash rate and percent current on time for each and every cycle of your flash pattern fall outside the figure.

As we have stated before, we believe that motor vehicle safety is best promoted by standardization of lighting signals. The information currently provided by signal lamps, such as flashers, is well understood by the driving public, instantly recognized, and unambiguously informative. We are concerned that very different flash patterns have the potential to cause confusion. Therefore, we plan in the near future to modify Standard No. 108 in a way that would preclude your design.

If you need further assistance, please contact George Feygin of my staff at this address or at (202) 366-2992.

Sincerely,

Jacqueline Glassman
Chief Counsel

ref:108
d.4/2/04

ID: 86-3.6

TYPE: INTERPRETATION-NHTSA

DATE: 05/02/86

FROM: AUTHOR UNAVAILABLE; Erika Z. Jones; NHTSA

TO: South Carolina Legislature

TITLE: FMVSS INTERPRETATION

TEXT:

The Honorable Ralph Davenport South Carolina Legislature P.O. 1301 Spartanburg, SC 20394

Dear Mr. Davenport:

This is to follow up on your phone conversation with Stephen Oesch of my staff concerning the effect of Federal regulations on the tinting of motor vehicle windows. I hope the following discussion answers your questions.

Some background information on how Federal motor vehicle safety laws and regulations affect the tinting of vehicle windows may be helpful. Our agency is authorized, under the National Traffic and Motor Vehicle Safety Act, to issue safety standards applicable to new motor vehicles and certain items of motor vehicle equipment. We have issued Federal Motor Vehicle Safety Standard No. 205, Glazing Materials, which specifies performance and location requirements for glazing used in vehicles. These requirements include specifications for minimum levels of light transmittance (70% in areas requisite for driving visibility, which includes all windows in passenger cars).

You first asked if the Federal motor vehicle safety standards apply to foreign vehicles sold in the United States. As with all our standards, Standard No. 205 applies to any new vehicle, whether made by a foreign or domestic company, manufactured for sale in the United States. Thus, no manufacturer or dealer is permitted to install solar films and other sun screen devices in new vehicles without certifying that the vehicle continues to be in compliance with the light transmittance and other requirements of the standard. Violation of Standard No. 205 can result in Federal civil penalties of up to $1,000 for each violation. In addition, a manufacturer of a vehicle that does not comply with our standards is required to remedy any noncompliances in its vehicles.

You also asked how Federal law affects businesses that tinted the windows of used vehicles. After a vehicle is first sold to a consumer, modifications to a vehicle are affected by section 108(a)(2)(A) of the Vehicle Safety Act. That section prohibits commercial businesses from tampering with safety equipment installed on a vehicle in compliance with our standards. Thus, no dealer, manufacturer, repair business or distributor can install a sun screen device for the owner of the vehicle, if the device would cause the window not to meet the requirements of Standard No 205. Violation of section 100(a)(2)(A) can result in Federal civil penalties of up to $1,000 for each violation.

Section 108(a)(2)(A) does not affect vehicle owners, who may themselves alter their vehicles as they please, so long as they adhere to all State requirements. Thus, under Federal law, the owner may install sun screening devices regardless of whether the installation adversely affects the light transmittance, However, the agency recommends that vehicle owners not install materials that would impair their vision and thus adversely affect safety. Individual States govern the operational use of vehicles by their owners and therefore it is within the authority of the States to preclude owners from using sun screens in their vehicles.

If you need further information, please let me know.

Sincerely,

Original Signed By

Erika Z. Jones Chief Counsel

ID: 21015.ogm

Mr. Murray West
P.O. Box 7081
Terre Haute, IN 47802

Dear Mr. West:

This responds to your letter requesting information about modifying the seat back in your new Ford Escort. I apologize for the delay in our response. You indicate that the angle of the seatback is uncomfortable for you and that you wish to have the seat modified so that the seat back would be perpendicular to the seat cushion. Representatives of the dealer who sold the car to you have indicated that it would be illegal for them to modify the seat in the manner you request. You ask that you be provided with the statutes or regulations which make modifying the existing seat illegal.

We would like to explain that the National Highway Traffic Safety Administration (NHTSA) is authorized to issue Federal motor vehicle safety standards (FMVSS) that set performance requirements for new motor vehicles and items of motor vehicle equipment. Manufacturers are required to assure that their products conform to our safety standards before they can be offered for sale. After the first sale of the vehicle, manufacturers, distributors, dealers, and repair businesses are prohibited from "knowingly making inoperative" any device or element of design installed on or in a motor vehicle in compliance with an applicable standard. In general, the "make inoperative" prohibition (49 U.S.C. 30122) requires businesses which modify motor vehicles to ensure that they do not remove, disconnect, or degrade the performance of safety equipment installed in compliance with an applicable standard. Violations of this prohibition are punishable by civil penalties of up to $1,100 per violation.

FMVSS No. 207, Seating systems (49 CFR 571.207; copy enclosed), sets forth minimum performance requirements for the seating systems installed in new passenger cars, such as your Ford Escort. FMVSS No. 207 does not contain any requirements that specify that the seat back must be within a certain range of angles to the seat back. The standard does, however, require that seats and seat backs meet certain strength requirements. Any modifications to the seat that would alter its original design could affect the seat's ability to meet these strength requirements. FMVSS No. 208, Occupant crash protection, sets forth certain performance requirements for frontal crash protection. Modifying the seat back angle in the manner you describe in your letter may have an impact on the ability of the seat belt and air bag to protect the driver in a crash. We do not know if modifying the adjustment mechanism on your seat to make the back perpendicular to the seat cushion would affect the seat's compliance with FMVSS No. 207 or No. 208 and how such a modified seat would perform in a crash.

You may wish to ask the manufacturer of your vehicle what effect modifying the seat back angle would have on its ability to meet FMVSS No. 207 or No. 208 as well as the seat's performance in a crash. If the seat back angle can be changed in the way that you describe without affecting the safety performance of the vehicle and its compliance with applicable Federal motor vehicle safety standards, the dealer would not be violating the "make inoperative" provisions described above by modifying the seat.

If you have other questions or require additional information, please contact Otto Matheke of my staff at this address or by phone at (202) 366-2992.

Sincerely,
Frank Seales, Jr.
Chief Counsel
ref:VSA
d.7/12/00

ID: Supreme_intl

Ms. Melissa A. Burt
Foley & Lardner, LLP
3000 K Street, NW, Suite 500
Washington, DC 20007-5143

Dear Ms. Burt:

This responds to your letter on behalf of your client, Supreme International Limited (Supreme). Supreme manufactures a Truck Mount Feed Processor, which is a livestock feed mixer mounted on a truck. You ask if the product is a "motor vehicle" subject to regulation by this agency. As explained below, our answer is yes.

You state that the Truck Mount Feed Processor is sold exclusively through farm equipment dealers and is not advertised for on-road use. You state that most of these vehicles never leave a farm after retail purchase, and that the vehicles travel on public roads on rare occasions for the purpose of transiting between farm locations or to obtain grain from a commodity barn. However, you also state that purchasers of these vehicles can obtain a certificate of title to permit registration and licensing under State motor vehicle laws.

Chapter 301 of Title 49 of the U.S. Code ("the Safety Act") authorizes the National Highway Traffic Safety Administration (NHTSA) to establish Federal motor vehicle safety standards (FMVSSs) applicable to new motor vehicles. Section 30102(a)(6) of that chapter defines "motor vehicle" as:

[A] vehicle driven or drawn by mechanical power and manufactured primarily for use on the public streets, roads, and highways, but does not include a vehicle operated only on a rail line.

We have issued a number of letters addressing this language. We have stated that vehicles equipped with tracks, agricultural equipment, and other vehicles incapable of highway travel are not motor vehicles. We have also determined that certain vehicles designed and sold solely for off-road use (e.g. , airport runway vehicles and underground mining vehicles) are not motor vehicles, even if they may be operationally capable of

highway travel. Also, vehicles are not motor vehicles if they were designed to be used primarily at off-road job sites and, although capable of being operated on public roads from one job site to another, their on-road use is only incidental to the primary purpose for which they were manufactured (e.g. , mobile cranes).

We would consider the feed mixer to be a "motor vehicle" for the purposes of our FMVSSs and regulations. The Truck Mount Feed Processors on-road use would be more than incidental. An incomplete motor vehicle (i.e. , a chassis cab) is used in its manufacture and, as you state, Supreme completes the vehicle in accordance with the incomplete vehicle document supplied by the chassis-cab manufacturer and can certify the vehicle as complying with the FMVSSs. No part of the manufacturing process alters the chassis cab such that its final configuration is limited to off-road use. You state that the vehicles may travel on public roads when traveling between farm locations or to obtain grain from a commodity barn. You also state that purchasers of these vehicles can obtain a certificate of title to permit registration and licensing as motor vehicles under State laws. Given these factors, we conclude that the vehicles are motor vehicles for purposes of the Safety Act.

If you have any additional questions, please contact Mr. Chris Calamita of my staff at (202) 366-2992.

Sincerely,

Jacqueline Glassman
Chief Counsel

ref:567
d.1/12/05

ID: 12414.ZTV

Mr. Art Maison
Purchasing Manager
Redneck, Inc.
2100 N. West By-Pass
Springfield, MO 66803

Dear Mr. Maison:

This replies to your letter of August 30, 1996, to Taylor Vinson of this Office, asking for an interpretation of the conspicuity requirements of Motor Vehicle Safety Standard No. 108.

You write that "the by-laws read that DOT-C is for the vehicles and trailers under 25,999 pounds require for that class. We would like to use these reflectors also for the DOT- C2, for the use on vehicles and trailers over 26,000 pounds."

We do not know the "by-law" to which you refer. Paragraph S5.7 of Standard No. 108 applies to all trailers of 80 or more inches overall width, and with a GVWR over 10,000 pounds. It does not distinguish between those over and under 26,000 pounds. Therefore, a trailer with a GVWR of 26,000 pounds must meet the same requirements of paragraph S5.7 as a trailer with a GVWR of 10,001 pounds.

We understand that you have discussed your problem with Pat Boyd, one of this agency's rulemaking engineers, and that your questions are: "What is the difference between DOT-C and DOT C-2" and "Does a reflex reflector have to be 2 inches wide, like reflective tape?"

Paragraph S5.7 permits a manufacturer to choose either reflex reflectors or reflective tape as the way to conform to the conspicuity requirements of Standard No. 108. "DOT-C" is the marking required for reflex reflectors, and is the reflector manufacturer's certification that the reflectors meet Standard No. 108 (Paragraph S5.7.2.3). "DOT- C2" is the marking required for reflective tape which has a width of not less than 50 mm (2 inches) and is the reflective tape manufacturer's certification that the tape meets Standard No. 108 (Paragraphs S5.7.1.3(d) and S5.7.1.5). Standard No. 108 does not require that reflex reflectors have a minimum width. Reflex reflectors are rated by the total light return per reflector, but reflective tape is rated by the light return per unit area. Standard No. 108 requires that one reflex reflector, meeting the DOT-C specification, have the same total light return as 100 mm of reflective tape meeting the DOT-C2 specification. We have seen reflex reflector bars 300 mm long certified to meet the DOT-C specification for each 100 mm segment. Standard No. 108 permits the use of these products even though they are only about 1 inch wide because they provide the same photometric performance as 300 mm of DOT -C2 reflective tape. I enclose a copy of the recent final rule which extended these requirements to truck tractors, and have circled language on p. 41357 which mentions this point.

I hope that this is responsive to your request. If you have any further questions, you may call Taylor Vinson at 202-366-5263.

Sincerely,

John Womack

Acting Chief Counsel

Enclosure

ref:108

d:9/25/96

ID: 14119.drn

Ms. Jo. Campfield
Vice President
Ultra Bond Licensing Corporation
2458 I-70 Business Loop, Ste. B-1
Grand Junction, CO 81501

Dear Ms. Campfield:

This responds to your request for an interpretation of this agency's laws that apply to your new product, EDGEGUARD, a clear material that is placed on the outer three inches or less of a windshield perimeter to prevent cracks. I apologize for the delay in responding.

As you are aware from past correspondence, the National Highway Traffic Safety Administration (NHTSA) has the authority to regulate the manufacture of new motor vehicles and motor vehicle equipment. NHTSA has promulgated Federal Motor Vehicle Safety Standard (FMVSS) No. 205, Glazing Materials, which specifies performance and location requirements for motor vehicle glazing. For windshields, Standard No. 205 specifies minimum levels of light transmittance (70 percent) and light stability; resistance to abrasion, delamination (humidity and boil tests), impact and penetration; and maximum levels of optical deviation and distortion. The various tests and criteria are contained in ANSI/SAE Z26.1, which is incorporated by reference in Standard No. 205.

NHTSA has stated in past interpretation letters that films such as the type your letter describes are not glazing materials themselves, and would not have to meet Standard No. 205. However, depending on who installs the glazing, installation of such films on new motor vehicles may be prohibited if, after installation, the vehicle glazing no longer meets the requirements of Standard No. 205, such as those for light transmittance, abrasion resistance and optical distortion.

A vehicle manufacturer or dealer placing your film on glazing in a new vehicle prior to sale of the vehicle must certify that the glazing continues to meet Standard No. 205. 49 U.S.C. Section 30112(a) prohibits any person from manufacturing for sale, offering for sale or selling any motor vehicle or equipment that fails to comply with applicable safety standards, including Standard No. 205. After the vehicle has been sold to the first purchaser, the owner may modify the vehicle as he or she pleases, subject to State requirements. Under Federal law, the owner could install your product on the vehicle whether or not such installation adversely affects the light transmittance and other properties of the vehicle's glazing. However, we urge consumers not to degrade the safety of their vehicles.

49 U.S.C. Section 30122(b) provides that a manufacturer, distributor, dealer or motor vehicle repair business "may not knowingly make inoperative" any device or element of design installed on or in a motor vehicle in compliance with an applicable motor vehicle safety standard. "Make inoperative" means to remove, disconnect or degrade the performance of a system or element of design installed pursuant to the FMVSSs. Thus, none of these persons may knowingly install your film on a vehicle for its owner if the installation would make inoperative the light transmittance or abrasion resistance of the vehicle glazing. Violations of this section may result in Federal civil penalties of up to $1,100 for each violation.

Because State law may affect the installation of your product on owners' vehicles, you should check the law in the States where you believe your product may be sold or installed for any applicable requirements.

I hope this information is helpful. If you have any further questions, please contact Dorothy Nakama of my staff at this address or at (202) 366-2992.

Sincerely,
John Womack
Acting Chief Counsel
ref:205
d.7/3/97

ID: 15634-r.wkm

Mr. Richard C. Kempf
Manager Technical Legislation
Navistar International
Transportation Corporation
2911 Meyer Road
Post Office Box 1109
Fort Wayne, IN 46801

Dear Mr. Kempf:

Please pardon the delay in responding to your letter to me stating that Navistar interprets Federal Motor Vehicle Safety Standard (Standard) No. 121, Air Brake Systems, to provide that the antilock brake systems (ABS) required by the standard need not be operational when the vehicle is switched by the driver to the all-wheel drive (AWD) mode. Your interpretation is not correct.

You stated that certain vehicles equipped with AWD normally operate in the two-wheel drive mode, but the AWD mode is selectable by the driver for severe service operation. You also correctly pointed out that paragraph S6.1.11 of Standard No. 121, when relating to special drive conditions, provides that such vehicles are tested with the AWD mode disengaged.

Paragraph S5.1.6(a) of Standard No. 121 provides:

Each single-unit vehicle manufactured on or after March 1, 1998, shall be equipped with an antilock brake system that directly controls the wheels of at least one front axle and the wheels of at least one rear axle of the vehicle. Wheels on other axles of the vehicle may be indirectly controlled by the antilock brake system.

This provision clearly requires that all single-unit vehicles equipped with air brake systems must also be equipped with ABS.

This is a general requirement that applies under all conditions.

There is no exception from this requirement for vehicles equipped with AWD, whether being operated in the 2WD or AWD mode.

The requirements of section S5 are tested in accordance with the conditions set forth in section S6. Paragraph S6.1.11 of that section provides, as one of the road test conditions:

A vehicle equipped with an interlocking axle system or a front wheel drive system that is engaged and disengaged by the driver is tested with the system disengaged (emphasis added).

Thus, an interlocking axle, or AWD, system controlled by the driver is disengaged for the road tests conducted under subsection S6.1. That does not mean, however, that ABS may be disengaged whenever the AWD system is in operation. The equipment requirements of S5 are not limited by the road test conditions of S6.

In summary, the ABS required by Standard 121 may not be disengaged or disabled when the vehicle is switched into AWD mode, but a vehicle in the AWD mode would not be required to meet the road test requirements of subsection S6.1. While the ABS may not be disabled, however, its operation could be modified to better suit off-road conditions, such as construction, logging, or mining operations, when AWD is selected.

I hope this information is helpful to you. Should you have any further questions or need additional information, please feel free to contact Walter Myers of my staff at this address or at (202) 366-2992.

Sincerely,
John Womack
Acting Chief Counsel
Enclosure
Ref:121
d.5/1/98