Controller Antilock Brake (CAB)

The antilock brake controller (CAB) is a microprocessor-based device that monitors wheel speeds and controls the antilock functions.
The primary functions of the CAB are:
^ monitor wheel speeds
^ detect wheel locking tendencies
^ detect wheel slip
^ control fluid pressure modulation to the brakes during antilock stop and traction control operation
^ monitor the system for proper operation
^ provide communication to the DRBIII(r) while in diagnostic mode
^ store diagnostic information in non-volatile memory
The CAB continuously monitors the speed of each wheel. When a wheel locking tendency is detected, the CAB will command the appropriate valve to modulate brake fluid pressure in its hydraulic unit. Brake pedal position is maintained during an antilock stop by being a closed system with the use of 3 accumulators. The CAB continues to control pressure in individual hydraulic circuits until a wheel locking tendency is no longer present. The CAB turns on the pump/motor during an antilock stop.
The antilock brake system is constantly monitored by the CAB for the proper operation. If the CAB detects a system malfunction, it can disable the antilock system and turn the antilock warning lamp. If the antilock function is disabled, the system will revert to standard base brake system operation.
The CAB inputs include the following:
^ four wheel speed sensors
^ brake lamp switch
^ ignition switch
^ battery voltage
^ diagnostic communication (PCI BUS)
The CAB outputs include the following:
^ ten valve/solenoid drivers
^ pump/motor actuation
^ ABS warning indicator actuation (PCI BUS)
^ red brake warning indicator actuation (PCI BUS)
^ diagnostic communication (PCI BUS)