Fuel Pump: Testing and Inspection
Fuel Pump Circuit Troubleshooting
If 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 turned to ON (II). If the fuel pump does not make noise, check as follows:
1. Turn the ignition switch to LOCK (0).
2. Remove PGM-FI main relay 2 (FUEL PUMP) (A) from the under-dash fuse/relay box.
3. Turn the ignition switch to ON (II).
4. Measure the 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 10.
NO -
Go to step 5.
5. Turn the ignition switch to LOCK (0).
6. Disconnect under-hood fuse/relay box connector D (8P).
7. Disconnect under-dash fuse/relay box connector G (21P).
8. Connect under-dash fuse/relay box connector G (21P) terminal No. 4 to body ground with a jumper wire.
9. Check for continuity between under-hood fuse/ relay box connector D (8P) terminal No. 6 and body ground.
Is there continuity?
YES -
Replace PGM-FI main relay 1.�
NO -
- Repair open in the wire between the under-hood fuse/relay box and the under-dash fuse/relay box.�
- If the wire is OK, replace the under-hood fuse/relay box Under-Hood Fuse/Relay Box Removal and Installation.�
10. Measure the 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 11.
NO -
- Check the No. 2 FUEL PUMP (15A) fuse in the under-dash fuse/relay box.�
- If needed, replace the under-dash fuse/relay box Under-Dash Fuse/Relay Box Removal And Installation.�
11. Turn the ignition switch to LOCK (0).
12. Connect PGM-FI main relay 2 (FUEL PUMP) 4P connector terminal No. 3 to body ground with a jumper wire.
13. Jump the SCS line with the HDS.
14. Disconnect PCM connector A (49P).
15. Check for continuity between body ground and PCM connector terminal A11.
Is there continuity?
YES -
Reinstall PGM-FI main relay 2, then go to step 16.
NO -
Repair open in the wire between PGM-FI main relay 2 (FUEL PUMP) and the PCM (A11).�
16. Connect PCM connector terminal A6 to body ground with a jumper wire.
17. Turn the ignition switch to ON (II).
18. Measure the voltage between PCM connector terminal A11 and body ground.
Is there battery voltage?
YES -
Go to step 19.
NO -
Replace PGM-FI main relay 2 (FUEL PUMP).�
19. Turn the ignition switch to LOCK (0).
20. Reconnect PCM connector A (49P).
21. Turn the ignition switch to ON (II), and measure the voltage between under-dash fuse/relay box connector F (34P) terminal No. 10 and body ground within 2 seconds.
Is there battery voltage?
YES -
Update the PCM if it does not have the latest software PCM Update, or substitute a known-good PCM, then recheck. If the symptom/indication goes away and the PCM was updated, troubleshooting is complete. If the symptom/indication goes away and the PCM was substituted, replace the original PCM Service and Repair.�
NO -
Go to step 22.
22. Turn the ignition switch to ON (II), and measure the voltage between under-dash fuse/relay box connector F (34P) terminal No. 10 and body ground after 2 seconds.
Is there battery voltage?
YES -
Go to step 23.
NO -
If needed, replace the under-dash fuse/relay box Under-Dash Fuse/Relay Box Removal And Installation.�
23. Turn the ignition switch to LOCK (0).
24. Remove the second row seat Second Row Seat Removal/Installation.
25. Pull the carpet back out of the way, then remove the access panel from the floor.
26. Turn the ignition switch to ON (II), and measure the voltage between fuel tank unit 4P connector terminal No. 2 and body ground within 2 seconds.
Is there battery voltage?
YES -
Go to step 31.
NO -
Go to step 27.
27. Turn the ignition switch to LOCK (0).
28. Remove PGM-FI main relay 2 (FUEL PUMP) (A) from the under-dash fuse/relay box.
29. Connect PGM-FI main relay 2 (FUEL PUMP) 4P connector terminals No. 1 and No. 2 with a jumper wire.
30. Turn the ignition switch to ON (II), and measure the voltage between fuel tank unit 4P connector terminal No. 2 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 tank unit 4P connector.�
31. Turn the ignition switch to LOCK (0).
32. Check for continuity between fuel tank unit 4P connector terminal No. 4 and body ground.
Is there continuity?
YES -
Replace the fuel pump Fuel Pump/Fuel Gauge Sending Unit Replacement.�
NO -
Repair open in the wire between the fuel tank unit 4P connector and G503.�