Electronic Brake Control Module: Description and Operation

CONTROLLER ANTILOCK BRAKE

(CAB) The CAB is mounted directly to the Hydraulic Control Unit (HCU) that includes a microprocessor and twelve solenoids that control valves that control brake pressure during antilock braking or traction control events. The CAB also has circuits that monitor the following:
^ Double brake switch outputs are monitored to determine whether or not to prepare for possible ABS braking
^ Wheel Speed Sensors are monitored to determine when a wheel is tending to lock up. The CAB will operate the valves in the HCU to control braking pressure during ABS braking
^ Detect ABS system related problems and take diagnostic action
^ Able to execute self-tests and output control commands

When equipped with Electronic Stability (ESP), the CAB also monitors the following:
^ The ESP looks at the Steering Angle Sensor value and monitors the speed of the inner and outer wheels to ensure that the values are plausible. The Steering Angle Sensor also monitors the speed that the steering wheel is turned.
^ The Lateral Acceleration/Yaw Rate Sensor is contained in one unit. The sensor measures side to side (lateral) motion and rotational motion (how fast the vehicle is turning).
^ The ESP uses data from the Brake Pressure Sensor to analyze how hard and fast that the driver wants to brake.