System Relay Circuit

NAME OF CODE:
System Relay Circuit

WHEN MONITORED:
Start-up cycle.

SET CONDITION:
The system relay is used to provide 12-volt power to the Controller, Anti-lock Brake (CAB) solenoid drivers and the pump/motor relay coil. The system relay is normally energized by the controller (pin 57) and is tested for proper function during the start-up cycle to see that it is not providing 12-volt output when not energized.

POSSIBLE CAUSES:
- Anti-lock Brake System (ABS) system relay control wire shorted to B(+)
- ABS System relay output circuit shorted to B(+)
- Stuck system relay contacts
- Open ground circuit to the relay box
- Failed CAB