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 turned on. If the fuel pump does not make noise, check as follows:

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

2. Remove the under-dash fuse/relay box Under-dash Fuse/Relay Box Removal/Installation, then remove PGM-FI main relay 2 (FUEL PUMP) (A) from the under-dash fuse/relay box.





3. Reinstall the under-dash fuse/relay box.

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

5. 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 13.

NO -

Go to step 6.

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

7. Disconnect under-hood fuse/relay box connector D (8P).

8. Jump the SCS line with the HDS.

9. Disconnect PCM connector A (49P).

10. Disconnect under-dash fuse/relay box connector G (21P).

11. Connect under-dash fuse/relay box connector G (21P) terminal No. 4 to body ground with a jumper wire.






12. Check for continuity between under-hood fuse/relay box connector D (8P) terminal No. 6 and body ground.





Is there continuity?

YES -

- Replace PGM-FI main relay 1.�
- If needed, replace the under-hood fuse/relay box Under-Hood Fuse/Relay Box Removal/Installation.�

NO -

Repair an open in the wire between the under-hood fuse/relay box and the under-dash fuse/relay box.�

13. 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 14.

NO -

- Check the No. 2 FUEL PUMP (15 A) fuse in the under-dash fuse/relay box.�
- If needed, replace the under-dash fuse/relay box Under-dash Fuse/Relay Box Removal/Installation.�

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

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






16. Jump the SCS line with the HDS.

17. Disconnect PCM connector A (49P).

18. Check for continuity between PCM connector terminal A16 and body ground.





Is there continuity?

YES -

Go to step 19.

NO -

Repair an open in the wire between PGM-FI main relay 2 (FUEL PUMP) and the PCM (A16).�

19. Remove the under-dash fuse/relay box Under-dash Fuse/Relay Box Removal/Installation, then reinstall PGM-FI main relay 2 (FUEL PUMP).

20. Reinstall the under-dash fuse/relay box.

21. Connect PCM connector terminal A7 to body ground with a jumper wire.





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

23. Measure the voltage between PCM connector terminal A16 and body ground.





Is there battery voltage?

YES -

Go to step 24.

NO -

Replace PGM-FI main relay 2 (FUEL PUMP).�

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

25. Reconnect PCM connector A (49P).

26. Within 2 seconds after turning the ignition switch to ON (II), measure the voltage between under-dash fuse/relay box connector F (34P) terminal No. 10 and body ground.





Is there battery voltage?

YES -

Update the PCM if it does not have the latest software, PCM Update or substitute a known-good PCM, then recheck. If the symptom/indication goes away with a known-good PCM, replace the original PCM Service and Repair.�

NO -

Go to step 27.

27. Within 2 seconds after turning the ignition switch to ON (II), measure the voltage between under-dash fuse/relay box connector F (34P) terminal No. 10 and body ground.





Is there battery voltage?

YES -

Go to step 28.

NO -

If needed, replace the under-dash fuse/relay box Under-dash Fuse/Relay Box Removal/Installation, then go to step 28.

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

29. Fold the driver's side rear seat forward, and pull back the carpet to expose the access panel.

30. Remove the access panel from the floor Fuel Tank Unit Removal/Installation.

31. Turn the ignition switch to ON (II), and measure the voltage between fuel tank unit 4P connector terminal No. 2 and body ground within 2 seconds.





Is there battery voltage?

YES -

Go to step 36.

NO -

Go to step 32.

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

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

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






35. Turn the ignition switch to ON (II), and measure the voltage between fuel tank unit 4P connector terminal No. 2 and body ground within 2 seconds.





Is there battery voltage?

YES -

Replace PGM-FI main relay 2(FUEL PUMP).�

NO -

Repair an open in the wire between PGM-FI main relay 2 (FUEL PUMP) and the fuel tank unit 4P connector.�

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

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





Is there continuity?

YES -

Replace the fuel pump Fuel Pump/Fuel Gauge Sending Unit Replacement.�

NO -

Repair an open in the wire between the fuel tank unit 4P connector and G602.�