ABS Main Relay: Description and Operation

Three relays are used to control the antilock brake system. The three relays are the pump/motor relay, the system relay, and the Antilock Brake System (ABS) amber warning lamp relay. The pump/motor relay and the system relay are located in the Controller Antilock Brake(CAB). If either the pump/motor relay or the system relay is diagnosed as not functioning properly, the Controller Antilock Brake(CAB) must be replaced.

The amber ABS warning lamp relay is located in the PDC. If the amber ABS warning lamp relay is diagnosed as not functioning properly, it can be replaced as a separate component of the PDC.