ABS Main Relay: Description and Operation

CIRCUIT OPERATION
The system relay is used for the operation of the Antilock Brakes (ABS) system. Power for the relay is supplied on the B57 circuit from cavity 57 of the Controller Anti Lock Brake (CAB).

Ground for the relay is on the Z1 circuit. This ground is spliced in with the pump motor, and terminates at the right strut tower.

When the system is operating normally, power for the contact side of the relay is supplied from the CAB on the B57 circuit. It passes through the relay to the Z1 ground and terminates at the right frame rail. If a problem is detected in the system, the relay is de-energized by circuit B57. This causes the ABS warning lamp in the instrument cluster to illuminate.