Checking Electrical Circuit

The fuel pump receives power from the fuel pump relay and the relay is energized by the engine control module (ECM). The test given below checks the relay's input (ground) from engine control module and the relay's output (B+ power) to the pump.

CHECK FUEL PUMP ELECTRICAL CIRCUIT
1. Check that the battery is charged and that fuse no. 18 is intact.

2. Fold down the rear seat and pull back the floor cover from the luggage compartment. Remove the access panel from above the fuel pump (rear right-hand corner).

3. While a helper listens at the fuel pump, turn the ignition key on. The pump should run briefly. If the pump runs, the circuit is probably functioning correctly. If the pump does not run, proceed to step 4.

NOTE: Listen carefully for the pump to run. Its operation is barely audible.

4. Remove the fuel pump relay and run the fuel pump. Operating Pump For Testing

^ If the pump runs, go to step 5.

^ If the pump does not run, go to step 6.

5. Remove the jumper wire from the relay panel. With the ignition key off, connect an ohmmeter between terminal 3 (corresponds to terminal 85 on the relay) in the relay panel and ground. Turn the key on. There should be a momentary ground signal.

^ If ground is present at terminal 85, the relay is probably faulty.

^ If ground is not present, check the wiring between relay panel terminal 85 and the engine control module. If no wiring faults can be found, the engine control module control unit may be faulty. Check the inputs to engine control module.




6. If the pump does not run as described in step 4, leave the jumper wire connected and disconnect the harness connector from the fuel pump. Check for voltage at the pump harness connector as shown in image.

^ If voltage is not present at the connector, check the wiring between the relay panel and the fuel pump harness connector. Check for power at the relay panel itself.

^ If voltage is present, remove the pump and check for internal shorts in the pump wiring. If no faults can be found, the pump is probably faulty.