Fuel Pump Relay Control Circuit

NAME OF CODE
Fuel Pump Relay Control Circuit

WHEN MONITORED
With the ignition key in the run position and battery voltage above 10 volts.

SET CONDITION
An open or shorted condition is detected in the fuel pump relay control circuit.

THEORY OF OPERATION
The fuel pump relay controls the 12-volt source to the fuel pump. The relay is located on the bulkhead or in the power distribution center. One side of the relay control coil is supplied with 12 volts when the ignition switch is turned to either the run or start position. The circuit is completed when the other side of the relay coil is grounded by the powertrain control module. The PCM grounds the relay for about one second when the ignition key is initially turned to the run or start position. Any additional grounding of the relay coil is performed only when the PCM detects engine RPM.

POSSIBLE CAUSES
- Relay coil open or shorted
- Fused ignition switch output circuit open
- Fuel pump relay control circuit is open or shorted
- Inoperative circuit driver in powertrain control module