Anti-Lock Brake Control Module

The anti-lock brake control module is mounted to the HCU.

It is an on-board diagnostic, non-repairable unit consisting of two microprocessors and the necessary circuitry for their operation. The anti-lock brake control module monitors system operation during normal driving as well as during anti-lock braking.

Anti-lock brake module operation is as follows:

• Under normal driving conditions, the microprocessor produces short test pulses to the solenoid valves that check the electrical system without any mechanical reaction.
• Impending wheel lock conditions trigger signals from the anti-lock brake control module that open and close the appropriate solenoid valves. This results in moderate pulsations in the brake pedal.
• The anti-lock brake module used in 4x4 application includes a G-sensor. It detects vehicle movement during a brake lockup event that is transferred to other wheels through the powertrain.

During normal braking, the brake pedal feel is identical to a standard brake system.

Most faults that occur in the anti-lock brake system will be stored as a Diagnostic Trouble Code (DTC) in the keep-alive memory of the anti-lock brake control module. The DTCs can be retrieved by following the on-board diagnostic procedures.