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

1. | Turn the ignition switch OFF.

2. | Remove the driver's side under cover.

3. | Remove the relay holder (A) from the under-dash fuse/relay box, and remove the PGM-FI main relay 2 (blue) (B) from the relay holder (A), after reinstall the relay holder (A) to the under-dash fuse/relay box.

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

5. | Measure voltage between the PGM-FI main relay 2 4P connector terminal No. 4 and body ground. Is there battery voltage? YES - Go to 6. NO - Repair open in the wire between the PGM-FI main relay 1 and the PGM-FI main relay 2.n

6. | Measure voltage between the PGM-FI main relay 2 4P connector terminal No. 1 and body ground. Is there battery voltage? YES - Go to 7. NO - Repair open in the wire between the under-dash fuse/ relay box and PGM-FI main relay 2.n

7. | Turn the ignition switch OFF.

8. | Disconnect the negative cable from the battery.

9. | Disconnect ECM/PCM connector E (31P).

10. | Check for continuity between the PGM-FI main relay 2 4P connector terminal No. 3 and ECM/PCM connector terminal E1. Is there continuity? YES - Go to 11. NO - Repair open in the wire between the PGM-FI main relay 2 and the ECM/PCM (E1).n

11. | Reinstall the PGM-FI main relay 2.

12. | Reconnect the negative cable from the battery.

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

14. | Measure voltage between ECM/PCM connector terminal E1 and body ground. Is there battery voltage? YES - Go to 15. NO - Replace the PGM-FI main relay 2.n

15. | Turn the ignition switch OFF.

16. | Disconnect the negative cable from the battery.

17. | Reconnect ECM/PCM connector E (31P).

18. | Reconnect the negative cable from the battery.

19. | Turn the ignition switch ON (II), and measure voltage between ECM/PCM connector terminal E1 and body ground within the first 2 seconds after the ignition switch was turned ON (II). Is there battery voltage? YES - Substitute a known-good ECM/PCM and recheck. If symptom/indication goes away, replace the original ECM/ PCM.n NO - Go to 20.

20. | Turn the ignition switch OFF.

21. | Remove the access panel from the floor.

22. | Measure voltage between the fuel pump 5P connector terminal No. 5 and body ground within the first 2 seconds after the ignition switch was turned ON (II). Is there battery voltage? YES - Go to 29. NO - Go to 23.

23. | Turn the ignition switch OFF.

24. | Remove the driver's side under cover.

25. | Remove the relay holder (A) from the under-dash fuse/relay box, and remove the PGM-FI main relay 2 (blue) (B) from the relay holder (A), after reinstall the relay holder (A) to the under-dash fuse/relay box.

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

27. | Turn the ignition switch ON (II).

28. | Measure voltage between the fuel pump 5P connector terminal No. 5 and body ground within the first 2 seconds after the ignition switch was turned ON (II). Is there battery voltage? YES - Replace the PGM-FI main relay 2.n NO - Repair open in the wire between the PGM-FI main relay 2 and the fuel pump 5P connector.n

29. | Turn the ignition switch OFF.

30. | Check for continuity between the fuel pump 5P connector terminal No. 4 and body ground. Is there continuity? YES - Replace the fuel pump.n NO - Repair open in the wire between the fuel pump 5P connector and G402.n