Inspection Bulletin 2012-03 (Antilock Brake System (ABS) Inspections)

Please refer to your attached CVSA Inspection Bulletin 2012-03 (Antilock Brake system (ABS) Inspections). On page one of the bulletin under "Guidance" the bulletin states "When power is initially provided to the ABS system, either when the vehicle's ignition switch is turned on, or when power is supplied to the brake lamp circuit on the trailer, the lamp momentarily turns on ...". Power is supplied to the brake lamp circuit when the driver applies the treadle valve/brake pedal. The actual inspection process outlined in the CVSA Inspection Bulletin, which begins on page 3 DOES NOT state "or when power is supplied to the brake lamp circuit on the trailer". The actual inspection process states that the lamp must activate when the ignition switch is turned on and states "Any other response indicates a malfunction of the ABS". The ABS inspection bulletin contained in the out of service criteria (the spiral bound copies) only contains the actual inspection process that does not have the "Guidance" portion contained on page 1, and does not mention "when power is supplied to the brake lamp circuit on the trailer". FMVSS 571.121 paragraph S.5.1.6.2 (a) and (b) states: S5.1.6.2 Antilock malfunction signal and circuit. (a) Each truck tractor manufactured on or after March 1, 1997, and each single unit vehicle manufactured on or after March 1, 1998, shall be equipped with an indicator lamp, mounted in front of and in clear view of the driver, which is activated whenever there is a malfunction that affects the generation or transmission of response or control signals in the vehicle's antilock brake system. The indicator lamp shall remain activated as long as such a malfunction exists, whenever the ignition (start) switch is in the “on” (“run”) position, whether or not the engine is running. Each message about the existence of such a malfunction shall be stored in the antilock brake system after the ignition switch is turned to the “off” position and automatically reactivated when the ignition switch is again turned to the “on” (“run”) position. The indicator lamp shall also be activated as a check of lamp function whenever the ignition is turned to the “on” (“run”) position. The indicator lamp shall be deactivated at the end of the check of lamp function unless there is a malfunction or a message about a malfunction that existed when the key switch was last turned to the “off” position. (b) Each truck tractor manufactured on or after March 1, 2001, and each single unit vehicle manufactured on or after March 1, 2001, that is equipped to tow another air-braked vehicle, shall be equipped with an electrical circuit that is capable of transmitting a malfunction signal from the antilock brake system(s) on one or more towed vehicle(s) (e.g., trailer(s) and dolly(ies)) to the trailer ABS malfunction lamp in the cab of the towing vehicle, and shall have the means for connection of this electrical circuit to the towed vehicle. Each such truck tractor and single unit vehicle shall also be equipped with an indicator lamp, separate from the lamp required in S5.1.6.2(a), mounted in front of and in clear view of the driver, which is activated whenever the malfunction signal circuit described above receives a signal indicating an ABS malfunction on one or more towed vehicle(s). The indicator lamp shall remain activated as long as an ABS malfunction signal from one or more towed vehicle(s) is present, whenever the ignition (start) switch is in the “on” (“run”) position, whether or not the engine is running. The indicator lamp shall also be activated as a check of lamp function whenever the ignition is turned to the “on” (“run”) position. The indicator lamp shall be deactivated at the end of the check of lamp function unless a trailer ABS malfunction signal is present.

I am confident that not only some of our inspectors (Idaho), but also other state inspectors are writing ABS violations when the trailer lamp is not activated with the ignition key, but is activated by the brake pedal. In some instances, the trailer may have a decal that states the lamp should activate with the ignition key ..... in some cases it does not, however it does cycle when the brake is applied. In my opinion, CVSA needs to revise their inspection process to include the application of the brakes to cycle the lamp. In the past, I have written a violation when the trailer contained a decal that states the lamp should cycle when the ignition key is switched on and it does not, but it does cycle when the brakes are applied (I usually note on the inspection that the lamp does not cycle with the ignition, but does cycle when the brakes are applied). Many newer trailers (2010 and newer) don't cycle with the key, but do cycle with the brake application. Again, only an opinion, if CVSA wants reliable data for their special study, they should revisit the inspection process as soon as possible. I am confident that they will see many ABS malfunction violations on inspections, because the lamp does not cycle with the ignition key.

Review the ABS Inspection Bulletin/Procedure and information to see if wording needs to be added to clarify to inspectors about having the driver apply the brake to activate the ABS MIL.