ID: nht92-9.31

DATE: February 3, 1992

FROM: Arthur J. Kuminski -- Design Engineer, Eberhard Manufacturing Company

TO: Paul Jackson Rice -- NHTSA

TITLE: None

ATTACHMT: Attached to letter dated 3/30/92 from Paul J. Rice to Arthur J. Kuminski (A39; Std. 206)

TEXT:

Eberhard Manufacturing manufactures industrial and vehicular hardware. We are presently in the final stages of prototyping a custom lock system for Grumman Olson to be used on their "Route Star Walk-in Vans". Enclosed are a picture and some specifications on the Route Star to help explain how the door is used.

The reason for my letter is to request further interpretation from your organization on the testing standards for sliding doors on cargo vans. The following standards are the ones I have questions about:

Standard No. 206 S4.3 Sliding Doors - The track and slide combination system or other supporting means for each sliding door shall not separate when a total transverse load of 4,000 pounds is applied, with the door in the closed position.

S5.3 Sliding Doors - Compliance with S4.3 shall be demonstrated by applying an outward transverse load of 2,000 pounds to the load bearing members of the door (4,000 pounds total). The demonstration may be performed either in the vehicle or with the door retention components in a bench test fixture.

1. I will need specifications on how to perform this test on a test fixture using the striker assembly and the door latch only.

2. What load must the system withstand in the primary locked position to pass the test?

3. Is their a load requirement that the system must withstand in the secondary locked position to pass the test?

If you have any questions, please call me. Thank you for your help.

ID: nht92-9.32

DATE: February 2, 1992

FROM: A. Volmerange

TO: Mr. Harper -- NHTSA

TITLE: None

ATTACHMT: Attached to letter dated 5/19/92 from Paul J. Rice to Anne Volmerange (A39; Std. 208; VSA 108(a)(2)(A))

TEXT:

My toyota dealer needs a written authorization from your office to install an old fashion three points belt on my 92 Tercel.

The two points belt which is on the car just don't fit me. I am five feet tall,and the shoulder belt ties either on my neck or on my breast. As these two body parts are too sensitive to take the pull of a restraining belt, I have to drive without it, in spite of the California Law.

Also, the holder of the shoulder belt can't be reached from my driving position since it is way behind the seat. This create a safety hazard since I would not be able to untie it in case of an emergency. One of my previous car burst in flames, and one of my hand opened the door, while the other untied the three points safety belt which I was wearing that day.

As a Registered Nurse, I am aware of the chest, neck and head injuries, and can't figure out why you have stopped using the three points belt. It was fitting all sizes drivers and all seat positions. Car dealers should be allowed to install them as many new cars owners hate the new system and don't use theirs belts.

ID: nht92-9.33

DATE: January 31, 1992

FROM: Paul Jackson Rice -- Chief Counsel, NHTSA

TO: S. Suzuki -- Managing Director, Suzusho Trading Co.

TITLE: Your ref: ST-9015/91

ATTACHMT: Attached to letter dated 10/16/91 from S. Suzuki to Director, Office of Public and Consumer Affairs, NHTSA (OCC 6611)

TEXT:

This responds to your letter of October 16, 1991, to the Director, Office of Public and Consumer Affairs, with reference to the "Safety Shot" lighting device that you have developed. You have enclosed photographs illustrating three types of this device in operation.

In brief, the device consists of a center red highmounted stop lamp, immediately flanked by amber lamps that serve as supplementary turn signal/hazard warning signal lamps. Although the photos are not entirely clear, the device appears to consist of segmented compartments in a common housing, with thicker dividers separating the signal and stop functions. Type I incorporates an L.E.D. and is mounted at the top of the rear window. Type II also incorporates an L.E.D. and is mounted at the bottom of the window. Type III is located at the top of the rear window and uses conventional bulbs for its light source. You have been referred to us by Chrysler Corporation. We assume that you approached Chrysler with a view towards having your device accepted as original motor vehicle equipment. You have asked for our views on whether it is possible to use this device in the U.S. market.

In the United States, the applicable Federal motor vehicle safety standard for rear lighting is Standard No. 108, Lamps, Reflective Devices, and Associated Equipment. Section S5.4 of Standard No. 108 does not allow a center high-mounted stop lamp to be physically combined with any other lamp or reflective device. Because Safety Shot appears to have a common housing for signalling and stopping functions, the lamps are "combined" within the meaning of the prohibition.

This means that the Safety Shot may not be used as original equipment on motor vehicles, and it may not be offered as a replacement for original equipment center highmounted stop lamps (required on each passenger car manufactured on or after September 1,1985).

If you wish to sell the Safety Shot as an accessory in the aftermarket, for passenger cars manufactured before September 1, 1985, different considerations apply. Installation of the Safety Shot by a manufacturer, distributor, dealer, or motor vehicle repair business is not permitted if it renders inoperative, in whole or in part, the function of any other rear lighting device.

The question, therefore, is whether the effectiveness of the function of any other rear lighting device is compromised by the Safety Shot to the extent that the other device's function is rendered, at the minimum, partially inoperative. We note that original equipment amber signal

lamps are not prohibited from flashing when the stop lamps are operating. It would not appear that the addition of the Safety Shot to a passenger car manufactured before September 1, 1985, would compromise the signals from the original turn signal and stop lamps in a manner to render them, at least, partially inoperative. However, the Safety Shot is subject to regulation by the individual States of the United States in which it is sold or used. We are unable to advise you on State laws, and suggest that you write for an opinion to American Association of Motor Vehicle Administrators, 4600 Wilson Boulevard, Arlington, Va. 22203.

Motor vehicles are also required to be manufactured to conform to Standard No. 111, Rearview mirrors. Under this standard, if installation of the Safety Shot prevents the vehicle from meeting the rearview mirror field of view requirements specified, the manufacturer, distributor, dealer, or motor vehicle repair business installing the Safety Shot must install a rear view mirror on the passenger side of the vehicle (as a practical matter, most vehicles in the U.S. are manufactured with this additional mirror).

ID: nht92-9.34

DATE: January 30, 1992

FROM: David Klopp -- Freedman Seating Company

TO: Mary Versailles -- NHTSA

TITLE: None

ATTACHMT: Attached to letter dated 2/14/92 from Paul Jackson Rice to David Klopp (A39; Std. 210)

TEXT:

Freedman Seating manufactures seating systems which are used in a variety of vehicles including shuttle buses, tour buses, etc. Examples of our seats are attached. The frames are mounted to the floor and, in many cases, to the wall of the vehicle also.

We would like an interpretation of FMVSS 210 regarding seats having multiple seating positions and with their seat belt anchorages located on the seat frame. Does the strength test in FMVSS 210 require simultaneous testing of all seat belt anchorages for each seat?

Please give me a call if you require additional information.

ID: nht92-9.35

DATE: January 29, 1992

FROM: J. Yoshimoto -- Manager, Technical Administration Dept., Koito Manufacturing Co., Ltd.

TO: James G. White -- Surface Group, Transport Canada

TITLE: Subject: CMVSS 108 "Lighting Equipment"; Reference: Canada Gazette Part II, Vol. 125, No. 26 dated December 18, 1991

ATTACHMT: Attached to letter dated 3/5/92 from Paul Jackson Rice to James G. White (A39; Std. 108)

TEXT:

Thank you for your kind consideration which you have always extended to us through SAE meeting.

We have studied the amended CMVSS 108 "Lighting Equipment" by Canada Gazette Part II Vol. 125, No. 26 dated December 18, 1991. And we would ask for your kind interpretation about "O" Mark on vertical/horizontal aim indicator of integral headlamp aiming device, specified in paragraph 108(28)(b)(ii)(A) and 108(28)(c)(ii)(A).

108(28)(b)(ii) a scale that has (A) a "O" mark that represents the vertical aim of zero degrees, ----------. 108(28)(c)(ii) a scale that has (A) a "O" mark that (I) presents the horizontal aim of zero-degrees ----------.

For these descriptions, it is unclear for us whether a mark of figure "O" be literally required for indicating zero degrees on vertical/horizontal aim indicator, or not.

In FMVSS 108 (U.S.), vertical/horizontal aim indicator of integral headlamp aiming device is required to have a zero mark, which does not necessarily mean a mark of figure "O", but may be just a reference mark. (Please refer to the attached copy of FMVSS 108 S7.7.5.2(a)(1) and (2).

Size of indicator is so small, that there is no space to add a figure "O" on it. Moreover, from the viewpoint of harmonization to FMVSS 108, CMVSS 108 should not require a figure "O" on the indicator, we think.

We would greatly appreciate if you would give us your kind interpretation to the above matter.

Thanking you for your kind and prompt reply in anticipation, we remain, With best regards.

ID: nht92-9.36

DATE: January 28, 1992

FROM: Paul Jackson Rice -- Chief Counsel, NHTSA; Signature by Stephen P. Wood

TO: William R. Willen, Esq. -- Managing Counsel, Product Legal Group, American Honda Motor Co., Inc.

TITLE: None

ATTACHMT: Attached to letter dated 12/16/91 from William R. Willen to Paul Jackson Rice (OCC 6833)

TEXT:

This responds to Honda's request for an interpretation of Federal Motor Vehicle Safety Standard No. 123, Motorcycle controls and displays. You stated that Honda is developing a braking system for motorcycles that would offer full proportioning front and rear when utilizing either the front hand control, or the rear control. You asked whether such a system would be permitted by the standard, particularly in light of section S5.2.1. As discussed below, such a braking system would be permissible under Standard No. 123.

By way of background information, the National Highway Traffic Safety Administration does not provide approvals of motor vehicles or motor vehicle equipment. Under the National Traffic and Motor Vehicle Safety Act, it is the responsibility of the manufacturer to ensure that its vehicles and equipment meet applicable requirements. The following represents our opinion based on the facts set forth in your letter.

S5.2.1, Control location and operation, includes the following language:

If a motorcycle is equipped with self-proportioning or antilock braking devices utilizing a single control for front and rear brakes, the control shall be located and operable in the same manner as a rear brake control.

Table 1 of Standard No. 123 provides that a rear wheel brake control must be a right foot control and must depress to engage. (Table 1 also includes an additional option that is not necessary to address in this letter.)

Since Honda's motorcycle would be equipped with a self-proportioning device utilizing a single control for front and rear brakes, it would be subject to this requirement. If Honda's "rear foot control" is one that is operated by the right foot and must be depressed to be engaged, that control would satisfy S5.2.1.

It is our interpretation that so long as one control meets the specified requirements for location and operation, additional controls serving the same purpose may be provided voluntarily by the manufacturer and need not meet those requirements. I note that this view is similar to a position taken in an April 26, 1983 interpretation letter to an addressee whose identity has been withheld for reasons of confidentiality. In that letter, the agency stated, in the context of discussing S5.2.1, that

"(u)se of ... a self-proportioning device does not preclude additional brake actuation devices." I am, for your information, enclosing a copy of that letter. In the situation at issue, we would consider the front hand control on Honda's design to be an "additional brake actuation device," and therefore, not precluded by Standard No. 123.

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

ID: nht92-9.37

DATE: January 28, 1992

FROM: Carl J. Clement -- Clement Associates

TO: Office of Chief Counsel, NHTSA

TITLE: None

ATTACHMT: Attached to letter dated 3/30/92 from Paul J. Rice to Carl J. Clement (A39; Std. 302; Std. 201)

TEXT:

I am in the process of inventing an automotive sun-visor which has the promise of improving upon the safety of currently used sun-visors. Within a week or so I shall have completed a mechanical protype which will serve as a means of testing electronics and optics. Enclosed is a patent disclosure which explains the device in greater detail.

I have been advised that, before proceeding further, I should research Federal and State agencies which have to do with regulations concerning automobiles, particularly automobile interiors. For example, are there regulations which would preclude the installation of an automatically-moving 3" high X 6" wide visor between the driver's eyes and the windshield?

I should appreciate your advice and a copy of any regulations with which I must comply, or which might be changed should the invention be viewed favorably by your or other government agencies.

ID: nht92-9.38

DATE: January 24, 1992

FROM: Larry J. French -- President and CEO, Magnascreen

TO: Office of Chief Counsel, NHTSA

TITLE: Reference: 49 CFR, Part 571, Docket No. 91-11, Notice 2, RIN2127-AD81, Federal Motor Vehicle Safety Standards; Rearview Mirrors - Reflectance

ATTACHMT: Attached to letter dated 3/26/92 from Paul J. Rice to Larry J. French (A39; Std. 111)

TEXT:

Magnascreen is presently developing electronically controlled dimmable (day/night) rearview mirror products for motor vehicles.

Magnascreen has reviewed the revised Code of Federal Regulations, Title 49, 571.111, standard number 111, for motor vehicle rearview mirror requirements referenced above. Upon review, we are requesting that the NHTSA comment on the validity of Magnascreen's interpretation which follows:

"When a multiple reflectance level mirror is not powered by the vehicle power source, the reflectance of the mirror can be returned to a minimum of 35% reflectance (either automatically or by driver operated controls) USING AN ALTERNATE POWER SOURCE." (A power source other than the one intended to (illegible) the mirror.)

This interpretation allows multiple reflectance mirror designs to use an alternate power source to achieve the specified failsafe operation called out in CFR 49, 579.111, para. S11, Rearview Mirrors.

Your timely response will be appreciated, as this interpretation impacts Magnascreen's mirror product designs.

ID: nht92-9.39

DATE: January 23, 1992

FROM: Paul Jackson Rice -- Chief Counsel, NHTSA; Signature by Stephen P. Wood

TO: Richard Gray -- Secretary of Sports Car Club of New Zealand, Inc.

TITLE: None

ATTACHMT: Attached to letter dated 11/11/91 from Richard Gray to Paul Jackson Rice (OCC 6724)

TEXT:

This responds to your letter asking for information about whether certain motor vehicles manufactured in the United States and imported into New Zealand comply with the requirements of the U.S. Federal Motor Vehicle Safety Standard No. 205, Glazing Materials, and Standard No. 208, Occupant Crash Protection. You explained that the New Zealand Ministry of Transport (MOT) is introducing new vehicle safety standards in an effort to align New Zealand's standards with those of the United States, Europe, Australia, and the United Kingdom. To that end, you stated that the MOT is requiring importers to ensure that the vehicles they import meet the relevant safety standards of these countries. You further indicated that you are responsible for providing proof to the MOT that certain privately imported, "low volume vehicles" (built in numbers less than 200 per year) comply with the requirements of their country of origin, or that the country has a special exemption for low volume vehicles. Accordingly, you asked for clarification of Standards No. 205 and 208, and other Federal regulations, as they would be applied to these vehicles. I am pleased to be able to provide the following information.

In the case of the United States, section 103 of the National Traffic and Motor Vehicle Safety Act (15 U.S.C. 1392) authorizes the National Highway Traffic Safety Administration (NHTSA) to issue Federal motor vehicle safety standards for new motor vehicles and new motor vehicle equipment. NHTSA has exercised this authority to issue a number of safety standards. The Safety Act then requires that all motor vehicles and motor vehicle equipment manufactured or sold in, or imported into, the United States comply with the safety standards adopted by NHTSA. Specifically, S108(a)(1)(A) of the Safety Act provides:

no person shall manufacture for sale, sell, offer for sale, or introduce or deliver introduction in interstate commerce, or import into the United States, any motor vehicle or item of motor vehicle equipment manufactured on or after the date any applicable Federal motor vehicle safety standard takes effect under this title unless it is in conformity with such standard and is covered by a certification issued under S114...

Generally speaking, then, to the extent that the vehicles you import are manufactured and sold in the United States, those vehicles would have to comply with all applicable safety standards, including Standards No. 205 and 208, regardless of the number of such vehicles produced by the manufacturer.

The fact that your letter is seeking proof that a motor vehicle ACTUALLY COMPLIES with applicable safety standards may, however, indicate a misunderstanding of the certification process in the United States. The process of certifying compliance with applicable safety standards under the Safety Act is substantially different than that used in many other countries. For instance, many European nations require manufacturers to deliver motor vehicles to a governmental entity for testing. After the governmental entity itself tests the vehicle, the government approves the vehicle and assigns an approval code. In countries using such a pre-sale approval certification process, the governmental entity would have specific information about the ACTUAL COMPLIANCE of vehicles with applicable standards.

In the United States, the Safety Act does not authorize NHTSA to do any pre-sale testing or approval of motor vehicles and motor vehicle equipment. Consequently, NHTSA does not have any "proof of actual compliance" of vehicles. Instead, the Safety Act establishes a self-certification process under which every manufacturer is required to certify that each of its products meets all applicable Federal safety standards. The vehicle manufacturer is required to certify that its vehicles comply with all applicable safety standards by permanently affixing a label to the driver's side door hinge pillar, door-latch post, or the door edge that meets the door-latch post. Among other things, that label must contain the statement: "This vehicle conforms to all applicable Federal motor vehicle safety standards in effect on the date of manufacture shown above."

Under the self-certification process used in the United States, NHTSA does conduct periodic enforcement tests on vehicles and items of equipment that have been certified by their manufacturer to ensure that the products do, in fact, comply with the safety standards. NHTSA also investigates alleged defects related to motor vehicle safety. In order for this agency to determine whether any of the vehicles imported into New Zealand were subject to an enforcement test or a defects investigation by this agency, you would have to provide us with specific descriptive information about each of the subject vehicles, including the date of manufacture.

It should be a simple exercise for you to check the area around the driver's side door of the vehicles in question to see if the manufacturer affixed a U.S. certification label, stating that the vehicle conforms to all applicable Federal motor vehicle safety standards. If the vehicle has such a label, there would not seem to be any reason for questioning the manufacturer's representation. On the other hand, if there is no such label, neither the vehicle's manufacturer nor anyone else has suggested that the vehicle conforms with the safety standards of the United States.

Finally, you asked whether the United States has any Federal regulations regarding the installation of registration plates on the front of vehicles. The answer is no; vehicle registration is a matter addressed by each of the individual States, not by the Federal government. Thus, the requirements for display of registration plates on the front of

vehicles differ from State to State. If you are interested in further information on the requirements of the individual states, you may wish to contact: American Association of Motor Vehicle Administrators, 4600 Wilson Boulevard, Arlington, Va. 22203, U.S.A.

ID: nht92-9.4

DATE: February 17, 1992

FROM: Stephen E. Selander -- Attorney, GM Legal Staff

TO: Paul Jackson Rice -- Office of the Chief Counsel, NHTSA

TITLE: Re: General Motors Corporation; FMVSS 101, 105; Request for Interpretations

ATTACHMT: Attached to letter dated 4/29/92 from Paul J. Rice to Stephen E. Selander (A39; Std. 101; Std. 105)

TEXT:

General Motors Corporation (GM) is currently preparing an electric vehicle (GMEV) which will be offered for sale in the near future. The GMEV contains basic design strategies that differ from traditional Internal Combustion Engine (ICE) vehicles. While these strategies are intended to comply with all Federal Motor Vehicle Safety Standards (FMVSS), questions have arisen about how to correctly apply the requirements of FMVSS 101 - Controls and Displays and 105 Hydraulic Brake Systems. The purpose of this letter is to seek the agency's concurrence with, or guidance regarding the proposed interpretations of these requirements.

FMVSS 101 PROPOSED INTERPRETATIONS

FUEL GAUGE REQUIREMENTS Proposed Interpretation: Permit electrically powered vehicles to use symbols that are appropriate for indicating electric power reserve.

FMVSS 101 S5.2.3 requires that information pertaining to fuel level be identified by the fuel level symbol found in Table 2 of FMVSS 101 or by the corresponding word: FUEL. This identification appears quite appropriate for traditional ICE vehicles that consume combustible fuels. However, the GMEV will not use combustible fuel; rather, it will rely on electrical energy stored in its battery packs. In this context the fuel symbol is inappropriate and potentially misleading.

As currently planned, the GMEV will be equipped with a gauge that will monitor battery charge as a percent of full charge. This gauge is to be identified by a symbol substantially similar to that found in FMVSS 101 Table 2 for Electrical Charge. We believe that this type of gauge is more appropriate for Electric Vehicles (EVs). It will allow the operator to readily monitor electric power remaining in the batteries and will serve as the functional equivalent of a fuel gauge found in traditional ICE vehicles.

It should be noted that the GMEV is being designed for domestic and international sale. In order to optimize cost effectiveness, it is imperative that we harmonize requirements whenever possible. To that end, we have reviewed our current design strategy for the "electric fuel" gauge with the appropriate European agencies. They have agreed that the ISO fuel symbol is inappropriate to indicate "electric fuel" and that a more appropriate symbol is the ISO battery symbol.

Therefore, we request the agency's concurrence that EVs are permitted to utilize symbols that are appropriate for identifying electric power reserve and not the FMVSS 101 fuel level symbol.

OIL PRESSURE REQUIREMENTS Proposed Interpretation: Allow the "Service Soon" telltale to indicate loss of powertrain oil pressure for the GMEV.

FMVSS 101 S5.2.3 requires information pertaining to oil pressure be indicated by the oil pressure symbol found in Table 2 of FMVSS 101 or by the corresponding word: OIL.

As currently planned, the GMEV will be equipped with a "Service Soon" telltale which will light in the event of a malfunction that could eventually cause damage to the vehicle powertrain, but does not require immediate attention. GM proposes to light this telltale in the event of a loss of oil pressure to the powertrain. We believe this to be a more appropriate telltale because the GMEV can continue to be driven without oil pressure.

The GMEV powertrain consists of an electric motor which drives a single speed transmission. Lubricating oil, contained in a reservoir below the powertrain, is splashed onto the gears and bearings of the powertrain by the motion of the vehicle and the turning of the transmission gears. Under normal conditions, the splashing oil sufficiently lubricates most of the powertrain pans except for the rear motor bearing. Oil is supplied to the rear bearing by an oil pump.

While a loss of oil pressure in traditional ICE vehicles causes significant damage in a very short period of time, a loss of oil pressure in the GMEV is not a catastrophic event. The normal motion of the GMEV supplies sufficient oil for it to continue to operate for some time. We estimate the GMEV would be able to operate approximately 500 miles without sustaining serious damage to the powertrain. This is a significant distance, especially for this commuter vehicle which has a maximum range between recharging of far less than 500 miles.

In the event of a loss of oil pressure, activating a traditional oil pressure telltale could send the wrong message to the operator of a GMEV. In its traditional context, an active oil pressure telltale means that severe engine damage is imminent. An explanation of low oil pressure found in a typical GM owner's manual of an ICE vehicle reads as follows:

CAUTION: An engine low on oil can catch fire. You could be seriously burned. If your oil warning light stays on, don't keep driving. Check your oil immediately and have the problem corrected.

The appropriate action by the operator is to stop the vehicle immediately, turn the engine off and correct the underlying condition.

In the event of a loss of oil pressure in the GMEV, the preceding action is not appropriate. It is not necessary for the driver to pull over immediately to prevent damage to the powertrain. Even if the operator did pull over, the oil could not be checked because the GMEV does not require traditional routine oil maintenance and therefore, is not equipped with an oil dip stick.

Therefore, in the event of a loss of oil pressure, we believe it is appropriate to light the "Service Soon" telltale which indicates that service is needed, but immediate action by the driver is not required.

FMVSS 105 PROPOSED INTERPRETATIONS

GM has previously submitted a letter from Mr. R. A. Rogers to the agency (USG 2886, dated July 2, 1991) which describes the brake system planned for the GMEV. This brake system consists of front hydraulic disc service brakes, rear electric drum service and parking brakes, four wheel ABS, and regenerative braking. USG 2886 also describes the regulatory requirements within FMVSS 105 which must be addressed, either through interpretation or rulemaking, to facilitate introduction of the GMEV brake system. A copy of USG 2886, Part III with the cover letter and the information for which confidential treatment is requested removed, is attached to this document. (Note: The content of USG 2886 Part III is identical to that which was originally submitted as USG 2886, July 1991; however, the document has been revised to reduce the portions for which GM continues to request confidential treatment. There are a few very minor inaccuracies in this document with respect to current design intent for the GMEV brake system. These slight differences in the brake system do not affect the FMVSS 105 interpretations being requested. It is likely that additional minor changes in the brake system will occur as it is refined. GM will keep the agency advised of any changes which have new FMVSS implications.)

GM's request for interpretations, as described in USG 2886, Part III, have not changed, so we respectfully request that the agency refer to the attachment for a detailed discussion of the issues which we propose be addressed by interpretation. A summary follows:

PROPOSED INTERPRETATIONS:

1. The GMEV parking brake is mechanically retained in accordance with the requirements of S5.2

2. The GMEV brake system is a "split service brake system" consisting of four subsystems, one at each wheel.

3. The four service brake subsystems may be certified to the requirements of S5.1.2 in accordance with the test procedure of S7.9.1 through S7.9.3 by disabling each subsystem in a way that does not affect the other three subsystems.

4. The GMEV brake system may be certified to the requirements of S5.1.3 in accordance with the test procedure of S7.10 by functionally disabling the Brake Control Unit (BCU). Such a procedure will completely disable the brake power assist, and since the electric motors within the hydraulic unit and the rear brake drums are separately disabled during S5.1.2 testing, there is no need to separately consider these electric motors when certifying to the requirements of S5.1.3.

5. The GMEV brake system may be certified to the requirements of S5.5 in accordance with the test procedure of S7.9.4 by functionally disabling the BCU. Since such a procedure will completely disable ABS and the variable proportioning function, no other testing is required in connection with S5.5.

6. Assuming the conditions established in proposed S6.2, regenerative braking is permitted to function normally when conducting the test procedures of S7. In particular, the phrase "service brakes shall be capable of stopping" (found in S5.1.4 and S5.1.5, for example) is not to be construed as prohibiting the normal operation for regenerative braking.

There is one additional FMVSS 105 interpretation that we would now request which was not discussed in USG 2886:

BRAKE TELLTALE ILLUMINATION

Proposed Interpretation: In addition to the explicit conditions for activation of the brake telltale set forth in S5.3 of the standard, permit illumination of the service brake telltale when an impending or latent brake system malfunction is detected during electrical diagnosis.

S5.3.1 of FMVSS 105 prescribes the conditions during which the brake telltale shall be illuminated. This section requires that the telltale illuminate when there is a gross loss of hydraulic pressure (or, alternatively, a drop in fluid level), a total functional electrical failure in the ABS or variable proportioning brake system, or when the parking brake is applied. On the GMEV, the brake telltale will illuminate whenever these prescribed conditions exist. However, a diagnostic capability will also exist to detect faults in the brake system which do not cause any of the conditions explicitly listed in S5.3.1. That is, a fault may be detected in a redundant component that does not affect brake system performance. However, such a fault would leave the brake system vulnerable to a single additional failure that could substantially diminish braking capability.

A specific example of this with respect to the GMEV's brake system could be a stuck solenoid within the hydraulic unit. Such a failure would not necessarily have an effect on brake system performance, nor would any of the explicit conditions listed in S5.3.1 be exhibited. Yet such a fault would decrease the overall reliability of the brake system and make the system more vulnerable to a significant degradation in performance should a second failure occur.

We believe that the opportunity should be afforded to alert the driver to brake system faults of the nature described above. Accordingly, we request the agency's concurrence that the language of S5.3.1 allows for illumination of the brake telltale when a fault is detected which INCREASES THE LIKELIHOOD of a substantial degradation in brake system performance, even if the fault in question does not strictly fall into any of the categories listed in that section of FMVSS 105.

SUMMARY

GM would be pleased to discuss with the agency any of the issues that we propose be handled through interpretation. Our overriding interest is to provide the agency with the information it needs to quickly resolve any and all compliance questions involving the applicability of FMVSS 101 and 105 to the GMEV so that design work can continue and plans to offer the GMEV to the public can be carried out promptly.

We appreciate the NHTSA's consideration of these proposed interpretations. If the agency has any questions or requires additional information please contact me at (313) 974-1704.

Attachment

USG 2938 - Attachment 1 -- USG 2886 Part III. (Text omitted here.)