Fuel Pump: Testing and Inspection
Fuel Pump Circuit TroubleshootingIf 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 left kick panel, then remove PGM-FI main relay 2 (FUEL PUMP) (A) from the under-hood fuse/relay box.
3. Turn the ignition switch ON (II)
4. Measure voltage between PGM-FI main relay 2 (FUEL PUMP) 4P connector terminal No. 3 and body ground.
Is there battery voltage?
YES - Go to step 5.
NO -
- Replace PGM-FI main relay 1 (FI MAIN)
- Replace the under-dash fuse/relay box.
5. Measure 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 6.
NO -
- Replace the No. 19 FUEL PUMP (15 A) fuse in the under-hood fuse/relay box.
- Replace the under-dash fuse/relay box.
6. Turn the ignition switch OFF.
7. Connect PGM-FI main relay 2 (FUEL PUMP) 4P connector terminal No. 4 to body ground with a jumper wire.
8. Turn the ignition switch OFF.
9. Jump the SCS line with the HDS.
10. Disconnect ECM/PCM connector E (31P).
11. Check for continuity between body ground and ECM/PCM connector terminal E17.
Is there continuity?
YES - Go to step 12.
NO - Repair open in the wire between PGM-FI main relay 2 (FUEL PUMP) and the ECM/PCM (E17).
12. Reinstall PGM-FI main relay 2 (FUEL PUMP).
13. Connect the ECM/PCM connector terminal E7 to body ground with a jumper wire.
14. Turn the ignition switch ON (II).
15. Measure voltage between ECM/PCM connector terminal E17 and body ground.
Is there battery voltage?
YES - Go to step 16.
NO - Replace PGM-FI main relay 2 (FUEL PUMP).
16. Turn the ignition switch OFF.
17. Reconnect ECM/PCM connector E (31P).
18. Open the SCS line with the HDS.
19. Turn the ignition switch OFF.
20. Turn the ignition switch ON (II), and measure voltage between ECM/PCM connector terminal E17 and body ground within the first 2 seconds after the ignition switch was turned on.
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 know good ECM/PCM, replace the original ECM/PCM.
NO - Go to step 21.
21. Turn the ignition switch OFF.
22. Remove the trunk floor.
23. Remove the access panel from the floor.
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.
Is there battery voltage?
YES - Go to step 30.
NO - Go to step 25.
25. Turn the ignition switch OFF.
26. Remove PGM-FI main relay 2 (FUEL PUMP).
27. Connect PGM FI main relay 2 (FUEL PUMP) 4P connector terminals No. 1 and No. 2 with a jumper wire.
28. Turn the ignition switch ON (II).
29. 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.
Is there battery voltage?
YES - Replace PGM-FI main relay 2 (FUEL PUMP).
NO - Repair open in the wire between PGM FI main relay 2 (FUEL PUMP) and the fuel pump 5P connector.
30. Turn the ignition switch OFF.
31. Check for continuity between fuel pump 5P connector terminal No. 4 and body ground.
Is there continuity?
YES - Replace the fuel pump.
NO - Repair open in the wire between the fuel pump 5P connector and G603.