Interpretation ID: nht75-1.16

DATE: 07/15/75

FROM: AUTHOR UNAVAILABLE; J. C. Schultz; NHTSA

TO: Toyota Motor Sales, USA, Inc.

TITLE: FMVSS INTERPRETATION

TEXT: This responds to Toyota's June 9, 1975, request for confirmation that S5.3.2 of Standard No. 10575, Hydraulic brake systems, requires a check of the brake system indicator lamp function only when the transmission shift lever (in the case of vehicles with automatic transmission) is in the "P" (park) position or the "N" (neutral) position. S5.3.2 specifies:

S5.3.2 All indicator lamps shall be activated as a check of lamp function either when the ignition (start) switch is turned to the "on" ("run") position when the engine is not running, or when the ignition (start) switch is in a position between "on" ("run") and "start" that is designated by the manufacturer as a check position.

The wording of S5.3.2 requires a check of lamp function without regard to the position of the transmission shift lever whenever the ignition switch is in one of the positions described. In the case of vehicles equipped with automatic transmission, this language does not reflect the National Highway Traffic Safety Administration's (NHTSA) intent that the check function occur during the process of starting the vehicle.

To incorporate the intended meaning of the requirement into the standard, the NHTSA will shortly issue an interpretative rule that modifies the language of S5.3.2 by limiting the check function to the park and neutral positions for vehicles with automatic transmission.

Sincerely,

ATTACH.

June 9, 1975

James B. Gregory -- Administrator, National Highway Traffic Safety Administration, U. S. Department of Transportation

Re: Interpretation of FMVSS No. 105-75

Dear Dr. Gregory:

We wish to request clarification of our interpretation of S5.3.2, Check of the Brake System Indicator Lamp Function, of FMVSS No. 105-75.

S5.3.2 reads as follows:

All indicator lamps shall be activated as a check of lamp function either when the ignition (start) switch is turned to the "on" ("run") position when the engine is not running, or when the ignition (start) switch is in a position between "on" ("run") and "start" that is designated by the manufacturer as a check position.

Our question is whether or not the indicator lamp must be activated in vehicles with automatic transmission when the neutral safety switch is open.

The neutral safety switch is installed on vehicles with automatic transmission and is designed to prevent engine starting when the transmission gear selector is in one of the positions other than P (Park) and N (Neutral).

We believe that this nonactivation of the indicator lamp when the engine cannot be started enables us to design a more reliable system without sacrificing any safety benefits.

We would very much appreciate your informing us of your opinion of our interpretation at your earliest convenience.

Thank you.

Very truly yours,

K. Nakajima -- Director/General Manager, Factory Representative Office