ABS Unit

ABS UNIT

SYSTEM SELF-TEST

When the ignition switch is turned-on the microprocessor is tested. If an error occurs during the test, a DTC will be set into the memory. However it is possible the DTC will not be stored in memory if the error has occurred in the module were the DTC's are stored.

The ABM contains a self check program that illuminates the ABS warning light when a system fault is detected. Faults are stored in 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.

ABM INPUTS

The ABM continuously monitors the speed of the vehicle by monitoring signals generated by the wheel speed sensors. The ABM determines a wheel locking tendency when it recognizes the axle is decelerating too rapidly. The ABM monitors the following inputs to determine when a wheel locking tendency may exists:

- Wheel Speed Sensors
- Brake Lamp Switch
- Brake Fluid Level Sensor (CAN C BUS)
- G-Sensor (4X4)

ABM OUTPUTS

The ABM requests the following outputs for antilock braking and brake warning information from the CCN via CAN C Bus:

- ABS Warning Lamp
- Brake Warning Lamp