Interpretation ID: nht71-1.29

DATE: 08/01/71 EST

FROM: AUTHOR UNAVAILABLE; Lawrence R. Schneider; NHTSA

TO: Toyota Motor Co., Ltd.

TITLE: FMVSS INTERPRETATION

TEXT: This is in response to your letter of July 23, 1971, in which you asked a question concerning the requirement in Standard No. 208 that the seat belt warning signals deactivate when the parking brake is applied.

Your question was whether the standard's requirement would be satisfied by a system in which the seat belt warning signals deactivate at the same point at which the parking brake warning light goes on, considering the fact that the warning light is generally set to go on at a point where the parking brake lever is partially extended but before the brake is actually engaged.

We would consider the standard's requirement to be satisfied by the system you describe. We agree that the presence of the parking brake warning light is a sufficient deterrent to driving the vehicle with the parking brake partially engaged.

Sincerely,

ATTACH.

July 23, 1971

Lawrence R. Schneider Acting Chief Counsel U.S. Dept. of Transportation National Hwy, Traffic Safety Adm.

Dear Mr. Schneider:

This is a request for clarification of the Motor Vehicle Safety Standard No. 208, "Occupant Crash Protection," Docket No. 69-7, Notice 10 (36FR12858).

Section 7.3.4(b) of the standard prohibits activation of the warning system when the parking brake is engaged on a vehicle that has a manual transmission. Monitors which detect whether or not the parking brake is engaged are necessary to meet this section. Therefore, for this purpose we intend to use a parking brake warning switch which actuates according to the position of the parking brake lever.

However, very often the parking brake lever position, where the parking brake begins to engage, is slightly different among cars because of adjustment, elongation of wire cables, and wear of brake shoes, etc. Therefore, the parking brake switch is adjusted so that the switch will be off at the bottom position of the parking brake lever, and it will come on when the lever is slightly pulled before the parking brake begins to engage. This adjustment is necessary to prevent the driver from unknowingly moving a car with a partially engaged parking brake.

The parking brake warning lamp could be on when the parking brake lever is not fully released and the brake itself is not engaged due to the adjustment or slack in this system, etc. In such cases, the seat belt warning system will not

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actuate, regardless of the transmission gear selector position.

Our understanding is that if the parking brake warning lamp is on, it may be considered that the parking brake is engaged because no driver should attempt to move a vehicle when the parking brake warning lamp is activated. We, therefore, do believe this system would meet the requirement of section 7.3.4(b).

Is our interpretation correct? When considering this information, please take into account that we do not have much lead time due to the proximity of the effective date.

Your prompt consideration and response will be very much appreciated.

Sincerely,

TOYOTA MOTOR CO., LTD.

Y. Kosaka Staff Engineer

cc: Mr. Hitchcock