Hydraulic Control Assembly - Antilock Brakes: Description and Operation

ABS Without Traction Control
This solenoid goes on when signals are received from the ECU and controls the pressure acting on the wheel cylinders thus controlling the braking force.

Fail safe function
If trouble occurs in the actuator solenoid valve circuit, the ECU cuts off current to the ABS solenoid valve relay and prohibits ABS control.


ABS With Traction Control
This solenoid goes on when signals are received from the ECU and controls the pressure acting on the wheel cylinders thus controlling the braking force.

Fail safe function:
If trouble occurs in the actuator solenoid circuit, the ECU cuts off current to the ABS & TRAC solenoid relay and prohibits ABS control and TRAC control.