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 (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 4P connector terminal No. 4 and body ground.





Is there battery voltage?

YES -

Go to step 5.

NO -

Test the PGM-FI main relay 1 Power Relay Test. If the relay is OK, replace the under-dash fuse/relay box Under-Dash Fuse/Relay Box Removal And Installation.�

5. Measure the voltage between PGM-FI main relay 2 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 Under-Dash Fuse/Relay Box Removal And Installation.�

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

7. Connect PGM-FI main relay 2 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 an open in the wire between PGM-FI main relay 2 and the PCM (A11).�

11. Reinstall PGM-FI main relay 2.

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.�

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

22. 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 27.

NO -

Go to step 23.

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

24. Remove PGM-FI main relay 2.

25. Connect PGM-FI main relay 2 4P connector terminals No. 1 and No. 2 with a jumper wire.






26. 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.�

NO -

Repair an open in the wire between PGM-FI main relay 2 and the fuel tank unit 5P connector.If the wire harness is OK, replace the under-dash fuse/relay box Under-Dash Fuse/Relay Box Removal And Installation.�

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

28. 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 an open in the wire between the fuel tank unit 5P connector and G502.�