Integrated Control Unit (ICU): Description

Fig 1: Integrated Control Unit

Courtesy of DAIMLERCHRYSLER CORP.

1 - ANTILOCK BRAKE MODULE (ABM)

2 - HYDRAULIC CONTROL UNIT (HCU)

3 - PUMP/MOTOR

The Hydraulic Control Unit (HCU) (2) and the Antilock Brake Module (ABM) (1) used with this antilock brake system are combined (integrated) into one unit, which is called the Integrated Control Unit (ICU).

Fig 2: ICU Mounting Location

Courtesy of DAIMLERCHRYSLER CORP.

1 - BODY FRAME RAIL

2 - FRONT MOUNTING SCREW

3 - ICU MOUNTING BRACKET

4 - REAR MOUNTING SCREWS

The ICU is located in the engine compartment, mounted to the left side body frame rail (1) right below the master cylinder (on left-hand-drive vehicles).

Two different ICU'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 traction control has a valve block that is approximately one inch longer than a HCU on a vehicle that is equipped with ABS only.

The ABS-only ICU consists of the following components: the ABM, 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 ABM, eight (build/decay) solenoid valves (four inlet valves and four outlet valves), two traction control solenoid valves, two hydraulic shuttle valves, valve block, fluid accumulators, a pump, and an electric pump/motor.

The replaceable components of the ICU are the HCU and the ABM. No attempt should be made to service any components of the HCU or ABM.

For additional information on the ABM, (Refer to ELECTRICAL/ELECTRONIC CONTROL MODULES/ANTILOCK BRAKE MODULE - DESCRIPTION) . For additional information on the HCU, (Refer to BRAKES - ABS/HYDRAULIC/MECHANICAL/HCU (HYDRAULIC CONTROL UNIT) - DESCRIPTION) .