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-dash 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).
- If needed, 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 -
- Check the No. 19 FUEL PUMP (15 A) fuse in the under-dash fuse/relay box.
- If needed, 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. Jump the SCS line with the HDS.
9. Disconnect PCM connector A (44P).
10. Check for continuity between body ground and PCM connector terminal A11.
Is there continuity?
YES - Go to step 11.
NO - Repair open in the wire between PGM-FI main relay 2 (FUEL PUMP) and the PCM (A11).
11. Reinstall PGM-FI main relay 2 (FUEL PUMP).
12. Connect PCM connector terminal A6to body ground with a jumper wire.
13. Turn the ignition switch ON (II).
14. Measure voltage between PCM connector terminal A11 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 PCM connector A (44P).
17. Exit the SCS mode with the HDS.
18. Turn the ignition switch OFF.
19. Turn the ignition switch ON (II), and measure voltage between under-dash fuse/relay box 39P connector terminal No. 3 and body ground within 2 seconds.
Is there battery voltage?
YES - Update the PCM if it does not have the latest software, or substitute a known-good PCM, then recheck. If the symptom/indication goes away with a known-good PCM, replace the original PCM.
NO - Go to step 20.
20. Turn the ignition switch OFF.
21. Remove the rear-seat back.
22. Remove the access panel from the floor.
23. 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?
YES - Go to step 28.
NO - Go to step 24.
24. Turn the ignition switch OFF.
25. Remove PGM-FI main relay 2 (FUEL PUMP).
26. Connect PGM-FI main relay 2 (FUEL PUMP) 4P connector terminals No. 1 and No. 2 with a jumper wire.
27. 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?
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.
28. Turn the ignition switch OFF.
29. 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 G502.