Module, Anti-Lock Brake System (Abs): Operation

The ABS module voltage is supplied by the ignition switch in the RUN position. The ABS module contains dual microcontrollers. A logic block in each microcontroller receives identical sensor signals. These signals are processed and compared simultaneously. The ABS module contains a self check program that illuminates the ABS warning light when a system fault is detected. Faults are stored in a diagnostic program memory and are accessible with the scan tool. ABS faults remain in memory until cleared, or until after the vehicle is started approximately 50 times. Stored faults are not  erased if the battery is disconnected.