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 PGM-FI main relay 2 (FUEL PUMP) (A).
3. Turn the ignition switch ON (II).
4. Measure voltage between PGM-FI main relay 2 (FUEL PUMP) 4P connector terminal No. 4 and body ground.
Is there battery voltage?
YES - Go to step 5.
NO - Repair open in the wire between PGM-FI main relay 1 (FI MAIN) and PGM-FI main relay 2 (FUEL PUMP).
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.
N0 -
- Repair open in the wire between the No. 11 IG FUEL PUMP (15 A) fuse and PGM-FI main relay 2 (FUEL PUMP).
- If needed, replace the No. 11 IG FUEL PUMP (15 A) fuse in the under-dash fuse/relay box.
- If needed, replace the dashboard wire harness (under-dash fuse/relay box).
6. Turn the ignition switch OFF.
7. Jump the SCS line with the HDS.
8. Disconnect ECM/PCM connector E (31P).
9. Connect PGM-FI main relay 2 (FUEL PUMP) 4P connector terminal No. 3 to body ground with a jumper wire.
10. Check for continuity between ECM/PCM connector terminal E17 and body ground.
Is there continuity?
YES - Go to step 11.
NO - Repair open in the wire between PGM-FI main relay 2 (FUEL PUMP) and the ECM/PCM (E17).
11. Reinstall PGM- FI main relay 2 (FUEL PUMP).
12. Connect ECM/PCM connector terminal E7 to body ground with a jumper wire.
13. Turn the ignition switch ON (II).
14. Within 2 seconds of turning on the ignition switch, measure voltage between ECM/PCM connector terminal E17 and body ground.
Is there battery voltage?
YES - Go to step 15.
NO - Replace PGM-FI main relay 2 (FUEL PUMP).
15. Turn the ignition switch OFF.
16. Reconnect ECM/PCM connector E (31P), and disconnect the jumper wire.
17. Open the SCS line with the HDS.
18. Turn the ignition switch ON (II), and measure voltage between ECM/PCM connector terminal E17 and body ground within 2 seconds.
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.
NO - Go to step 19.
19. Turn the ignition switch OFF.
20. Remove the center console.
21. Remove the access panel from the floor.
22. Turn the ignition switch ON (II), and measure voltage between fuel tank unit 4P connector terminal No. 2 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 OFF.
24. Remove PGM- FI main relay 2 (FUEL PUMP).
25. Connect PGM-FI main relay 2 (FUEL PUMP) 4P connector terminals No. 1 and No. 2 with a jumper wire.
26. Turn the ignition switch ON (II), and measure voltage between fuel tank unit 4P connector terminal No. 2 and body ground.
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 tank unit 4P connector.
27. Turn the ignition switch OFF.
28. Check for continuity between fuel tank unit 4P connector terminal No. 4 and body ground.
Is there continuity?
YES - Replace the fuel pump.
NO - Repair open in the wire between the fuel tank unit 4P connector and G403.