MODULE-ANTILOCK BRAKE
DESCRIPTION
The Antilock Brake Module (ABM) (1) is mounted to the Hydraulic Control Unit (HCU) (3) and operates the ABS system .
OPERATION
The ABM voltage source is through 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. Pull up on the ABM harness connector (4) release and remove connector.
3. Remove the pump connector from the ABM.
4. Remove the brake lines (1) from the ABM (2).
5. Remove the ABM (2) mounting nuts (3) .
6. Remove the ABM unit from the vehicle.
7. Remove the ABM module (1) mounting screws (2) from the ABM unit (3) (Refer to 5 - BRAKES/HYDRAULIC/MECHANICAL/HCU (HYDRAULIC CONTROL UNIT) - DISASSEMBLY).
INSTALLATION
NOTE: If the ABM module (1) is being replaced with a new ABM module it must be reprogrammed with the use of a scan tool.
1. Install ABM module (1) to the ABM unit (3) (Refer to 5 - BRAKES/HYDRAULIC/MECHANICAL/HCU (HYDRAULIC CONTROL UNIT) - ASSEMBLY).
2. Install mounting screws (2) . Tighten to 2 N·m (16 in. lbs.).
3. Install the ABM unit (2) to the vehicle.
4. Install the ABM mounting bracket nuts (3) and tighten to 14 N·m (125 in. lbs.).
5. Install brake lines (1) to the ABM unit (2) and tighten to 20 N·m (180 in. lbs.).
6. Install the wiring harness connector (4) to the ABM unit and push down on the release to secure the connector.
7. Install negative battery cable to the battery.
8. Bleed ABS brake system (Refer to 5 - BRAKES - STANDARD PROCEDURE).