Brake Fluid Pump Relay: Description and Operation

ABS Without Traction Control
The ABS motor relay supplies power to the ABS pump motor. While the ABS is activated, the ECU switches the ABS motor relay ON and operates the ABS pump motor.


Fail safe function:
If trouble occurs in the ABS pump motor, the ECU cuts off current to the ABS control (solenoid) relay and prohibits ABS control.


ABS With Hydraulic Brake Booster System
The ABS motor relay supplies power to the hydraulic brake booster pump motor. While the ABS is activated, the ECU switches the motor relay ON and operates the hydraulic brake booster pump motor.

Fail safe function:
If trouble occurs in the ABS control (motor) relay circuit, the ECU cuts off current to the ABS control (solenoid) relay and prohibits ABS control.


ABS With Traction Control
The ABS & TRAC motor relay supplies power to the ABS & TRAC pump motor. While the ABS is activated, the ECU switches the ABS & TRAC motor relay ON and operates the ABS & TRAC pump motor.

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