Electronic Brake Control Module: Description and Operation

The Antilock Brake Control Module (ABCM) receives wheels speed readings from each antilock brake sensor and processes this information to determine if an ABS event is necessary. The antilock brake sensor electrically senses each tooth of the antilock brake sensor indicators as it passes through the antilock brake sensor's magnetic field.

The ABCM continuously monitors and compares the rotational speed of each wheel, and when it detects an impending wheel lock, modulates hydraulic pressure to the appropriate brake caliper. This is accomplished by the ABCM triggering the Hydraulic Control Unit (HCU) to open and close the appropriate solenoid valves. Once the affected wheel returns to normal speed, the ABCM returns the solenoid valves to their normal position, and normal (base) braking resumes.

The ABCM is self monitoring. When the ignition switch is turned to the RUN position, the ABCM will do a preliminary electrical check , and at approximately 12 km/h (8 mph) the pump motor is turned on for approximately one half second. Any malfunction of the ABS will cause the ABS to shut off and the yellow ABS warning indicator to illuminate. However, normal power assisted braking remains.