2013-02 Antilock Brake Systems Inspection Bulletin

Certain anti-lock brake equipped trailers have external ABS malfunction indicator lamps that activate when the brake pedal is applied. According to manufacturers, this is how they are designed to function. However, the CVSA bulletin #2013-02, "Antilock Brake System Inspections," indicates this is as violation. In the attached Bendix ABS manual -- See page 14, paragraph (b): b. For brake-light-only powered ABS: Each time the brakes are applied, the indicator lamp will illuminate for approximately three (3) seconds and then turn off. See page 17, paragraph (b): b. For brake-light-only powered ABS: Each time the brakes are applied, the indicator lamp will come on for approximately three (3) seconds and then turn off.

Motor carriers may receive a violation for a defective ABS due to the trailer external lamp activating when the brakes are applied. Bendix and Haldex indicate this is how the lamp is designed to work and should not be a violation. Motor carriers are receiving critical defects, precluding the trailer from receiving a CVSA decal on a Level 1 or Level 5 inspection. Motor carriers are having to remove the trailer from service to be diagnosed by a mechanic, which causes loss of use and unnecessary expenses. States are burdened with DataQ requests for the violations and carriers are burdened with proving the violation was erroneously issued on a trailer that operated the way it was manufactured.

Confirm with brake manufacturers that the external malfunction indicator lamp is supposed to activate upon brake pedal application and extinguish within a few seconds, as outlined in their owner's manual. If the external brake lamp is not a violation for activating upon brake pedal application, amend the ABS bulletin and associated flowchart. On the USA flowchart, the box on the right reads in part: "There is a power unit violation when the trailer ABS cycles when the service brake is applied (not receiving constant power). (393.55(c)(1)or(2))" This may need clarified to conform to the ABS manual provided.