Interpretation ID: aiam3207
Ross Frame & Axle
Inc.
P.O. Box 343
Ross
OH 45061;
Dear Mr. Cain: This responds to your January 8, 1980, letter asking whether th computers connected to the air brake systems of trucks can be disconnected.; The computerized braking systems were used by some manufacturers t comply with the requirements of Standard No. 121, *Air Brake Systems*. Part of that safety standard was invalidated by the court in *PACCAR v. NHTSA*, 532 F2d. 632 (9th Cir. 1978). In that decision, the Court invalidated portions of the standard involving some of the road test requirements for trucks and trailers. The computer systems that you question were usually added for purposes of complying with the invalidated antilock sections of the standard.; The agency has previously addressed the question of whether th antilock system can be disconnected in light of the court decision. Section 108(a)(2)(A) of the National Traffic and Motor Vehicle Safety Act (the Act) states that--; >>>No manufacturer, distributor, dealer, or motor vehicle repai business shall knowingly render inoperative, in whole or part, any device or element of design installed on or in a motor vehicle or item of motor vehicle equipment in compliance with an applicable Federal motor vehicle safety standard....<<<; The issue is whether the antilock was 'installed .... in complianc with an applicable .... standard.' Because the NHTSA concluded that the 'no lockup' and 60-mph stopping distances have been invalidated from the effective date of the standard, we also conclude that a manufacturer could not have actually been installing antilock systems or the brake performance levels in satisfaction of such a requirement, however much intended. Therefore, the NHTSA would not consider it to be a violation of S 108(a)(2)(A) for a commercial facility to disconnect an antilock system or to provide instructions on how it can safely be disconnected. The NHTSA recommends that any modification be undertaken only after consulting with the manufacturer about the safest configuration of the particular vehicle.; Sincerely, Frank Berndt, Chief Counsel