Electronic Brake Control Module: Description and Operation

- The anti-lock brake control module is mounted on the hydraulic control unit located in the front of the engine compartment on the LH side of the vehicle.
- The anti-lock brake control module operates as follows:
^ If the anti-lock brake control module senses that a wheel is about to lock, the anti-lock brake control module activates the appropriate inlet valve in the brake pressure control valve block, which closes that valve. This prevents any more fluid from entering the affected brake.
^ The anti-lock brake control module then looks at the wheel again. If it is still decelerating, the anti-lock brake control module opens the normally closed outlet valve in the brake pressure control valve block, which decreases the pressure trapped in the line.
^ Impending wheel lock conditions trigger signals from the anti-lock brake control module that open and close the appropriate solenoid valves in the brake pressure control valve block. This results in moderate pulsations in the brake pedal (2455).
^ During normal braking, the brake pedal feel will be identical to a standard brake system.
- Most malfunctions which occur in the anti-lock brake system will store a diagnostic trouble code (DTC) in the keep-alive random access memory of the anti-lock brake control module.
- The DTCs can be retrieved following the on-board diagnostic procedures
- Power is provided to the anti-lock brake control module through three separate fused lines for electronic logic control, hydraulic pump motor and solenoid valves.

ABS CONTROL MODULE SIGNALS
Signal inputs to the anti-lock brake control module are:
- battery positive voltage (B +).
- front brake anti-lock sensors and rear brake anti-lock sensor signals.
- stoplight switch brake on/off signal.
- diagnostic data link.

Signal outputs are:
- instrument cluster ABS indicator.
- diagnostic data link.