## 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 5P connector terminal No. 3 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 5P 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. | Connect PGM-FI main relay 2 5P connector terminal No. 5 to body ground with a jumper wire.

9. | Wait 10 seconds.

10. | Connect the ECM test harness and test pin box between the ECM and connectors.

11. | Check for continuity between test pin box terminal No. 89 and body ground. Is there continuity? YES - Go to 12. NO - Repair open in the wire between the PGM-FI main relay 2 and ECM connector No. 4 terminal No. 8 (test pin box terminal No. 89).n

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

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

14. | Measure voltage between pin box terminal No. 89 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. | Turn the ignition switch ON (II), and measure voltage between pin box ternimal No.89 and body ground. Is there battery voltage? YES - Substitute a known-good ECM and recheck. If symptom/indiction goes away, replace the original ECM.n NO - Go to 17.

17. | Turn the ignition switch OFF.

18. | Remove the access panel from the floor.

19. | 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 26. NO - Go to 20.

20. | Turn the ignition switch OFF.

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

22. | 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.

23. | Connect the PGM-FI main relay 2 5P connector terminals No. 1 and No. 2 with a jumper wire.

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

25. | 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

26. | Turn the ignition switch OFF.

27. | 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