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 on. If the fuel pump does not make noise, do this:
1. Turn the ignition switch to LOCK (0).
2. Open the fuse access panel (A), then remove PGM-FI main relay 2 (B) 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 4P connector terminal No. 4 and body ground.
Is there battery voltage?
YES -
Go to step 5.
NO -
Test PGM-FI main relay 1 Testing and Inspection. If the relay is OK, replace the under-dash fuse/relay box Under-dash Fuse/Relay Box Removal And Installation (USA Models).�
5. 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 6.
NO -
- Check the No. 20 FUEL PUMP (15 A) fuse in the under-dash fuse/relay box.�
- If the fuse is OK, replace the under-dash fuse/relay box Under-dash Fuse/Relay Box Removal And Installation (USA Models).�
6. Turn the ignition switch to LOCK (0).
7. Connect PGM-FI main relay 2 4P connector terminal No. 3 to body ground with a jumper wire.
8. Jump the SCS line with the HDS.
9. Disconnect ECM/PCM connector A (49P).
10. Check for continuity between body ground and ECM/PCM connector terminal A16.
Is there continuity?
YES -
Go to step.
NO -
Repair open in the wire between PGM-FI main relay 2 and the ECM/PCM (A16).�
11. Reinstall PGM-FI main relay 2.
12. Connect ECM/PCM connector terminal A7 to body ground with a jumper wire.
13. Turn the ignition switch to ON (II).
14. Measure the voltage between ECM/PCM connector terminal A16 and body ground.
Is there battery voltage?
YES -
Go to step 15.
NO -
- Repair open in the wire between the under-dash fuse/relay box and the ECM/PCM(A7, A16).�
- If the wires are OK, replace PGM-FI main relay 2 Testing and Inspection.�
15. Turn the ignition switch to LOCK (0).
16. Reconnect ECM/PCM connector A (49P).
17. Turn the ignition switch to ON (II), and measure the voltage between under-dash fuse/relay box connector B (36P) terminal No. 32 and body ground within 2 seconds.
Is there battery voltage?
YES -
Update the ECM/PCM if it does not have the latest software ECM/PCM Update, or substitute a known-good ECM/PCM Initial Inspection and Diagnostic Overview, then recheck. If the symptom/indication goes away with a known-good ECM/PCM, replace the original ECM/PCM Service and Repair.�
NO -
Turn the ignition switch to LOCK (0), then go to step 18.
18. Turn the ignition switch to ON (II), and measure the voltage between under-dash fuse/relay box connector B (36P) terminal No. 32 and body ground after 2 seconds.
Is there battery voltage?
YES -
Go to step 19.
NO -
Replace the under-dash fuse/relay box Under-dash Fuse/Relay Box Removal And Installation (USA Models).�
19. Turn the ignition switch to LOCK (0).
20. Remove the center console Service and Repair.
21. Remove the parking brake lever, then remove the access panel from the floor Fuel Tank Unit Removal/Installation.
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 27.
NO -
Go to step 23.
23. Turn the ignition switch to LOCK (0).
24. Remove PGM-FI main relay 2.
25. Connect PGM-FI main relay 2 4P connector terminals No. 1 and No. 2 with a jumper wire.
26. Turn the ignition switch to ON (II), and measure the voltage between fuel tank unit 4P connector terminal No. 2 and body ground.
Is there battery voltage?
YES -
Replace PGM-FI main relay 2.�
NO -
Repair open in the wire between PGM-FI main relay 2 and the fuel tank unit 4P connector.�
27. Turn the ignition switch to LOCK (0).
28. 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 G502 [1][2]Harness.�