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 (A) from the auxiliary under-hood fuse/relay box (to the left of the 12 volt battery).
3. Turn the ignition switch to ON (II).
4. Measure the voltage between PGM-FI main relay 2 4P connector terminal No. 4 and body ground.
Is there battery voltage?
YES -
Go to step 6.
NO -
Go to step 5.
5. Measure the voltage between under-dash fuse/relay box B connector (36P) terminal No. 8 and body ground.
Is there battery voltage?
YES -
Repair an open in the wire between PGM-FI main relay 2 and the under-dash fuse/relay box .
NO -
- Replace PGM-FI main relay 1.
- If needed, replace the under-dash fuse/relay box (USA model) Under-Dash Fuse/Relay Box Removal and Installation (USA Models), (Canada model) Under-Dash Fuse/Relay Box Removal and Installation (Canada Models).
6. Measure the voltage between PGM-FI main relay 2 4P connector terminal No. 1 and body ground.
Is there battery voltage?
YES -
Go to step 8
NO -
Go to step 7.
7. Measure the voltage between under-dash fuse/relay box B connector (36P) terminal No. 14 and body ground.
Is there battery voltage?
YES -
Repair an open in the wire between PGM-FI main relay 2 and the under-dash fuse/relay box .
NO -
- Check the No. 20 FUEL PUMP (15A) fuse in the under dash fuse/relay box.
- If the fuse is OK, replace the under-dash fuse/relay box (USA model) Under-Dash Fuse/Relay Box Removal and Installation (USA Models), (Canada model) Under-Dash Fuse/Relay Box Removal and Installation (Canada Models).
8. Turn the ignition switch to LOCK (0).
9. Connect PGM-FI main relay 2 4P connector terminal No. 3 to body ground with a jumper wire.
10. Jump the SCS line with the HDS.
11. Disconnect PCM connector A (49P).
12. Check for continuity between PCM connector terminal A30 and body ground.
Is there continuity?
YES -
Go to step 13.
NO -
Repair an open in the wire between PGM-FI main relay 2 and the PCM (A30).
13. Reinstall PGM-FI main relay 2.
14. Connect PCM connector terminal A7 to body ground with a jumper wire.
15. Turn the ignition switch to ON (II).
16. Measure the voltage between PCM connector terminal A30 and body ground.
Is there battery voltage?
YES -
Go to step 17.
NO -
Replace PGM-FI main relay 2.
17. Turn the ignition switch to LOCK (0).
18. Remove the rear seat cushion Rear Seat Removal / Installation.
19. Remove the access panel from the floor.
20. Disconnect the fuel tank unit 4P connector.
21. Reconnect PCM connector A (49P).
22. 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 23.
NO -
Go to step 25.
23. Turn the ignition switch to LOCK (0).
24. 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 an open in the wire between the fuel tank unit and G602.
25. Turn the ignition switch to LOCK (0).
26. Remove PGM-FI main relay 2 (A) from the auxiliary under-hood fuse/relay box (to the left of the 12 volt battery).
27. Connect PGM-FI main relay 2 4P connector terminals No. 1 and No. 2 with a jumper wire.
28. 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 -
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 -
Repair an open in the wire between the fuel tank unit and PGM-FI main relay 2.