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 driver's 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. 4 and body ground.
Is there battery voltage?
YES - Go to step 5.
NO -
- Replace PGM-FI main relay 1 (FI MAIN).
- If needed, replace driver's 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 driver's under-dash fuse/relay box.
- If needed, replace the driver's under-dash fuse/relay box.
6. Turn the ignition switch OFF.
7. Connect PGM-FI main relay 2 (FUEL PUMP) 4P connector terminal No. 3 to body ground with a jumper wire.
8. Jump the SGS line with the HDS.
9. Disconnect PCM connector A (49P).
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.
15. Turn the ignition switch OFF.
16. Reconnect PCM connector A (49P).
17. Open the SCS line with the HDS.
18. Turn the ignition switch ON (II), and measure voltage between driver's 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 19.
19. Turn the ignition switch OFF.
20. Remove the second row seat.
21. Remove the access panel from the floor.
22. Turn the ignition switch ON (II), and measure voltage between fuel tank unit 5P connector terminal No. 5 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 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 tank unit 5P connector.
27. Turn the ignition switch OFF.
28. Check for continuity between fuel tank unit 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 tank unit 5P connector and G603.