DTC C1604 Ecu Hardware Error: General Description

The HECU consists of an ECU (Electronic Control Unit) and a HCU (Hydraulic Control Unit).

The HCU portion of the assembly contains a pump motor, solenoid valves, and accumulator.

Increase and decrease of hydraulic pressure is operated by electronic motor, according to a measured signal by wheel speed sensor.

The function of HCU is to increase, decrease or maintain the hydraulic pressure supplied to a wheel cylinder by operating return pump according to HECU control signal while ABS control is active.

The ECU monitors various sensor and switch inputs.

These inputs are used to make decisions regarding HCU component operation.