Pump Relay

Pump Relay
The Electronic Control Unit (ECU) activates the Antilock Brake System (ABS) pump relay when the brake system goes into the ABS mode through grounding at pin 15.

Activated pin 15 = 0 Volts
Non-activated pin 15 = 12 Volts.

The pump will run until the travel sensor informs the ECU that it has gone back 1 step from its original position.

The ECU is also activated for 30 m/sec: the first time the car reaches 30 km/h after the ignition has been turned on.
- To complete self diagnosis, the ECU needs a speed signal from the pump motor.