Hydraulic Control Unit
| ITEM | DESCRIPTION |
|---|---|
| 1 | Rear right brake outlet port |
| 2 | Left front brake outlet port |
| 3 | Right front brake outlet port |
| 4 | Left rear brake outlet port |
| 5 | Primary circuit inlet port |
| 6 | Secondary circuit inlet port |
| 7 | Hydraulic control unit |
| 8 | Electrical connector |
| 9 | Control module |
The Hydraulic Control Unit (HCU) is an integral part of the Anti-lock Brake System (ABS) control module. The HCU is installed in the rear corner of the engine compartment, on the passenger side.
The HCU is a four channel unit that modulates the supply of hydraulic pressure to the brakes under the control of the ABS. The primary and secondary outlet ports of the master cylinder are connected to the primary and secondary inlet ports of the HCU. The primary circuit in the HCU supplies hydraulic pressure to two separate outlet ports, for one front brake and one rear brake. The secondary circuit provides hydraulic pressure to two separate outlet ports for the other front and rear brakes.
The HCU has three brake operating modes:
- Normal braking/Electronic Brake Force Distribution (EBD)
- ABS braking
- Active braking.
Details of these operating modes are given in the Braking Control article of this repair information. For additional information, Refer to: BRAKING CONTROL SYSTEM