Fuel Pump: Testing and Inspection

Fuel Pump Circuit Troubleshooting

If you suspect a problem with the fuel pump, check that the fuel pump actually runs; when it is on, you will hear some noise if you listen to the fuel fill port with the fuel fill cap removed. The fuel pump should run for 2 seconds when the ignition switch is first turned to ON (II). If the fuel pump does not make noise, check as follows:

1. Turn the ignition switch to LOCK (0).

2. Remove the left kick panel, Service and Repair then remove PGM-FI main relay 2 (FUEL PUMP) (A) from the under-dash fuse/relay box.






3. Turn the ignition switch to ON (II).

4. Measure the voltage between PGM-FI main relay 2 (FUEL PUMP) 4P connector terminal No. 4 and body ground.

Is there battery voltage?
YES - Go to step 5.

NO - Do the PGM-FI main relay 1 (FI MAIN) test. Power Relay Test If the relay is OK, replace the under-dash fuse/relay box.






5. Measure the voltage between PGM-FI main relay 2 (FUEL PUMP) 4P connector terminal No. 1 and body ground.

Is there battery voltage?
YES - Go to step 6.

NO -
- If needed, replace the No. 19 FUEL PUMP (15 A) fuse in the under-dash fuse/relay box.

- If needed, replace the under-dash fuse/relay box.







6. Turn the ignition switch to LOCK (0).

7. Connect PGM-FI main relay 2 (FUEL PUMP) 4P connector terminal No. 3 to body ground with a jumper wire.






8. Jump the SCS line with the HDS.

9. Disconnect PCM connector A (49P).

10. Check for continuity between body ground and PCM connector terminal A11.

Is there continuity?
YES - Go to step 11.

NO - Repair open in the wire between PGM-FI main relay 2 (FUEL PUMP) and the PCM (A11).






11. Reinstall PGM-FI main relay 2 (FUEL PUMP).

12. Connect PCM connector terminal A6 to body ground with a jumper wire.

13. Turn the ignition switch to ON (II).






14. Measure the voltage between PCM connector terminal A11 and body ground.

Is there battery voltage?
YES - Go to step 15.

NO - Replace PGM-FI main relay 2 (FUEL PUMP).






15. Turn the ignition switch to LOCK (0).

16. Reconnect PCM connector A (49P).

17. Exit the SCS mode with the HDS.

18. Turn the ignition switch to LOCK (0).

19. Turn the ignition switch to ON (II), and measure the voltage between under-dash fuse/relay box 39P connector terminal No. 3 and body ground within 2 seconds.

Is there battery voltage?
YES - Update the PCM if it does not have the latest software, PCM Update or substitute a known-good PCM, Initial Inspection and Diagnostic Overview then recheck. If the symptom/indication goes away with a known-good PCM, replace the original PCM. Service and Repair

NO - Go to step 20.






20. Turn the ignition switch to LOCK (0).

21. Remove the rear seat-backs. Rear Seat Removal/Installation

22. Remove the access panel from the floor.

23. Turn the ignition switch to ON (II), and measure the voltage between fuel pump 5P connector terminal No. 5 and body ground within 2 seconds.

Is there battery voltage?
YES - Go to step 28.

NO - Go to step 24.






24. Turn the ignition switch to LOCK (0).

25. Remove PGM-FI main relay 2 (FUEL PUMP).

26. Connect PGM-FI main relay 2 (FUEL PUMP) 4P connector terminals No. 1 and No. 2 with a jumper wire.






27. Turn the ignition switch to ON (II), and measure the voltage between fuel tank unit 5P connector terminal No. 5 and body ground within 2 seconds.

Is there battery voltage?
YES - Replace PGM-FI main relay 2 (FUEL PUMP).

NO - Repair open in the wire between PGM-FI main relay 2 (FUEL PUMP) and the fuel tank unit 5P connector.






28. Turn the ignition switch to LOCK (0).

29. Check for continuity between fuel tank unit 5P connector terminal No. 4 and body ground.

Is there continuity?
YES - Replace the fuel pump.

NO - Repair open in the wire between the fuel tank unit 5P connector and G502.