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 glove box, then 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) 5P connector terminal No. 5 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) 5P connector terminal No. 1 and body ground.
Is there battery voltage?
YES - Go to step 6.
NO - Repair open in the wire between the under-dash fuse/relay box No. 17 FUEL PUMP (15 A) fuse and PGM-FI main relay 2 (FUEL PUMP).
6. Turn the ignition switch OFF.
7. Jump the SCS line with the HDS.
8. Disconnect ECM/PCM connector E (31P).
9. Check for continuity between PGM-FI main relay 2 (FUEL PUMP) 5P connector terminal No. 3 and ECM/PCM connector terminal E17.
Is there continuity?
YES - Go to step 10.
NO - Repair open in the wire between PGM-FI main relay 2 (FUEL PUMP) and the ECM/PCM (E17)
10. Reinstall PGM-FI main relay 2 (FUEL PUMP).
11. Connect ECM/PCM connector terminal E7 to body ground with a jumper wire.
12. Turn the ignition switch ON (II).
13. Measure voltage between ECM/PCM connector terminal E17 and body ground.
Is there battery voltage?
YES - Go to step 14.
NO - Replace PGM-FI main relay 2 (FUEL PUMP).
14. Turn the ignition switch OFF.
15. Remove the jumper wire, then reconnect ECM/PCM connector E (31P).
16. Open the SCS line with the HDS.
17. 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 for 2 seconds?
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 18.
18. Turn the ignition switch OFF.
19. Remove the center console.
20. Fold back the rear floor covering until the access panel is accessible. Remove the access panel from the floor.
21. Turn the ignition switch ON (II), and measure voltage between fuel pump 5P connector terminal No. 5 and body ground within 2 seconds.
Is there battery voltage for 2 seconds?
YES - Go to step 27.
NO - Go to step 22.
22. Turn the ignition switch OFF.
23. Remove PGM-FI main relay 2 (FUEL PUMP).
24. Connect PGM-FI main relay 2 (FUEL PUMP) 5P connector terminals No. 1 and No. 2 with a jumper wire.
25. Turn the ignition switch ON (II).
26. Measure voltage between fuel pump 5P connector terminal No. 5 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 pump 5P connector.
27. Turn the ignition switch OFF.
28. 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 G552.