Interpretation ID: aiam1794
Attorney
Volkswagen of America
Inc.
Englewood Cliffs
N.J. 07632;
Dear Mr. Riechel: This responds to Volkswagen's December 11, 1974, request for determination that a brake system indicator lamp which activates only upon application of the brake pedal with a control force if 50 pounds or more to signal a 'gross loss of pressure' would meet the requirements of S5.3.3 of Standard no. 105-75, *Hydraulic brake systems*:; >>>S5.3.3 Each indicator lamp activated due to a condition specified i S5.3.1 shall remain activated as long as the condition exists, whenever the ignition (start) switch is in the 'on' ('run') position, whether or not the engine is running.<<<; Your question arises as to the meaning of the phrase in S5.3.3. whic requires that the lamp 'remain activated as long as the condition exists', with reference to the condition described in S5.3.1(a) as 'gross loss of pressure (such as caused by rupture of a brake line but not by a structural failure if a housing that is common to two or more subsystems)'. You point out that a condition involving loss if pressure cannot exist in the absence of pressure, that is, after control force is remove from the brake pedal.; While the NHTSA has always believed that the requirement in questio can best be satisfied by an indicator lamp which remains activated after the loss of pressure has occurred, we agree that the language in question could be more clearly drafted to express this intent.Accordingly, we plan to propose an amendment to the standard to eliminate this ambiguity. The proposed effective date of the amendment will be far enough in the future so that any new design changes required to comply may be effected without undue burden on affected manufacturers.; Because we conclude that the reliance Volkswagen has placed on it alternative reading if S5.3.3 can be justified in this case, we would accept the limited warning offered by the system you describe as satisfying the current requirement in S5.3.3 with regard to S5.3.1(a).; Yours truly, Richard B. Dyson, Assistant Chief Counsel