Fuel Pump Relay Circuit Check

FUEL PUMP RELAY CIRCUIT CHECK




Circuit Description
When the ignition switch is turned ON, the powertrain control module (PCM)/engine control module (ECM) will activate the fuel pump relay and run the in-tank fuel pump. The fuel pump will operate as long as the engine is cranking or running and the PCM/ECM is receiving ignition reference pulses.
If there are no reference pulses, the PCM/ECM will shut off the fuel pump within 2 seconds after the ignition switch is turned ON.

Diagnostic Aids
An intermittent problem may be caused by a poor connection, rubbed through wire insulation, or a broken wire inside the insulation.

Steps 1 To 10:

Steps 11 To 13:

Test Description
The number(s) below refer to step(s) on the diagnostic table.
3. This step checks for the PCM/ECM providing a ground for the operation of the fuel pump relay.
7. By confirming that the wiring is OK using Steps 2 through 6, it can be determined that the fuel pump relay is at fault.
9. After determining that there is no ground being provided by the PCM/ECM to the fuel pump relay, the fault is either the PCM/ECM or the wiring between the PCM/ECM and the fuel pump relay.