MODULE-ANTILOCK BRAKES
DESCRIPTION
NOTE: If the ABM module is replaced it must be
initialized using the scan tool.
The Antilock Brake Module (ABM) (1) is mounted to
the Hydraulic Control Unit (HCU) (2) and operates the
ABS system.
OPERATION
NOTE: If the ABM nodule is replaced it must be initialized using the scan tool.
The ABM voltage is supplied by the ignition switch in the RUN position. The ABM contains dual microprocessors. A
logic block in each microprocessor receives identical sensor signals. These signals are processed and compared
simultaneously. The ABM 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.
REMOVAL
1. Remove the negative battery cable from the battery.
2. Install a brake pedal prop rod.
3. Siphon the master cylinder.
8E - 254
ELECTRONIC CONTROL MODULES - SERVICE INFORMATION
WK