Integrated Control Module (ICU)
DESCRIPTIONIntegrated Control Unit (ICU):
The Hydraulic Control Unit (HCU) and the Controller Antilock Brake (CAB) used with this antilock brake system are combined (integrated) into one unit, which is called the Integrated Control Unit (ICU). The ICU is located on the driver's side of the front suspension cradle under the vehicl.
Two different HCU's and CAB's are used on this vehicle depending on whether or not the vehicle is equipped with traction control. The HCU on a vehicle equipped with ABS and traction control has a valve block housing that is approximately 1 inch longer on the low pressure fluid accumulators side than a HCU on a vehicle that is equipped with only ABS.
The ABS-only ICU consists of the following components: the CAB, eight (build/decay) solenoid valves (four inlet valves and four outlet valves), valve block, fluid accumulators, a pump, and an electric motor.
The ABS with traction control ICU consists of the following components: the CAB, eight (build/decay) solenoid valves (four inlet valves and four outlet valves), two traction control (ASR) solenoid valves, two hydraulic shuttle valves, valve block, fluid accumulators, a pump, and an electric pump/motor. On vehicles with traction control, the ICU contains a total of 10 solenoid valves. The two ASR valves and solenoids are used to isolate the brake system during traction control operation.
The replaceable components of the ICU are the HCU and the CAB. No attempt should be made to service any individual components of the HCU or CAB.
OPERATION
For information on the operation of the ICU, refer to:
- Controller Antilock Brakes (CAB)
- Hydraulic Control Unit (HCU)
- Hydraulic Circuits And Valve Operation.