## 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 fuse cover.

3. | Remove PGM-FI main relay 2 (A) from the under-dash fuse/relay box.

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

5. | Measure voltage between PGM-FI main relay 2 4P connector terminal No. 3 and body ground. Is there battery voltage? YES - Go to 6. NO - Repair open in the wire between PGM-FI main relay 1 and PGM-FI main relay 2.n

6. | Measure voltage between 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 ECM/PCM connector E (31P).

9. | Check for continuity between PGM-FI main relay 2 4P connector terminal No. 4 and ECM/PCM connector terminal E1*1 (E10)*2. Is there continuity? YES - Go to 10. NO - Repair open in the wire between PGM-FI main relay 2 and the ECM/PCM (E1*1 (E10)*2).n

10. | Reinstall PGM-FI main relay 2.

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

12. | Measure voltage between ECM/PCM connector terminal E1*1 (E10)*2 and body ground. Is there battery voltage? YES - Go to 13. NO - Replace PGM-FI main relay 2.n

13. | Turn the ignition switch OFF.

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

15. | Turn the ignition switch ON (II), and measure voltage between ECM/PCM connector terminal E1*1 (E10)*2 and body ground within the first 2 seconds after the ignition switch was turned ON (II). Is there battery voltage? YES - Update the ECM/PCM if it does not have the latest software, or substitute a known-good ECM/PCM, then recheck. If the symptom/indication goes away with a known-good ECM/PCM, replace the original ECM/ PCM.n NO - Go to 16.

16. | Turn the ignition switch OFF.

17. | Remove the access panel from the floor.

18. | 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 25. NO - Go to 19.

19. | Turn the ignition switch OFF.

20. | Remove the fuse cover.

21. | Remove PGM-FI main relay 2 (A) from the under-dash fuse/relay box.

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

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

24. | Measure voltage between 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 PGM-FI main relay 2.n NO - Repair open in the wire between PGM-FI main relay 2 and the fuel pump 5P connector.n

25. | Turn the ignition switch OFF.

26. | Check for continuity between 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