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 the driver's dashboard lower cover Driver's Dashboard Lower Cover Removal / Installation.
3. Remove PGM-FI main relay 2 (A) from the driver's under-dash fuse/relay box.
4. Turn the ignition switch to ON (II).
5. 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 13.
NO -
Go to step 6.
6. Turn the ignition switch to LOCK (0).
7. Remove PGM-FI main relay 1 (A) and the ETCS control relay (B) from the under-hood fuse/relay box.
8. Jump the SCS line with the HDS.
9. Disconnect the engine wire harness 13P connector (C101).
10. Disconnect driver's under-dash fuse/relay box connector F (33P).
11. Connect PGM-FI main relay 1 4P connector terminal No. 2 to body ground with a jumper wire.
12. Check for continuity between driver's under-dash fuse/relay box connector F (33P) terminal No. 31 and body ground.
Is there continuity?
YES -
Replace the driver's under-dash fuse/relay box; USA model Driver's Under-Dash Fuse/Relay Box (Driver's MICU) Removal and Installation (USA Models), Canada model Driver's Under-Dash Fuse/Relay Box (Driver's MICU) Removal and Installation (Canada Models).
NO -
- Repair an open in the wire between the under-hood fuse/relay box and the driver's 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.
13. Measure the voltage between PGM-FI main relay 2 4P connector terminal No. 2 and body ground.
Is there battery voltage?
YES -
Go to step 14.
NO -
- Check the No. 9 FUEL PUMP (20 A) fuse in the driver's under-dash fuse/relay box.
- If the fuse is OK, replace the driver's under-dash fuse/relay box; USA model Driver's Under-Dash Fuse/Relay Box (Driver's MICU) Removal and Installation (USA Models), Canada model Driver's Under-Dash Fuse/Relay Box (Driver's MICU) Removal and Installation (Canada Models).
14. Turn the ignition switch to LOCK (0).
15. Connect PGM-FI main relay 2 4P connector terminal No. 3 to body ground with a jumper wire.
16. Jump the SCS line with the HDS.
17. Disconnect PCM connector A (49P).
18. Check for continuity between body ground and PCM connector terminal A11.
Is there continuity?
YES -
Go to step 19.
NO -
Repair an open in the wire between PGM-FI main relay 2 and the PCM (A11).
19. Reinstall PGM-FI main relay 2.
20. Connect PCM connector terminal A6 to body ground with a jumper wire.
21. Turn the ignition switch to ON (II).
22. Measure the voltage between PCM connector terminal A11 and body ground.
Is there battery voltage?
YES -
Go to step 23.
NO -
Replace PGM-FI main relay 2.
23. Turn the ignition switch to LOCK (0).
24. Reconnect PCM connector A (49P).
25. Turn the ignition switch to ON (II), and measure the voltage between driver's under-dash fuse/relay box connector F (33P) terminal No. 22 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 with a known-good PCM, replace the original PCM Service and Repair.
NO -
Go to step 26.
26. Turn the ignition switch to ON (II), and measure the voltage between driver's under-dash fuse/relay box connector F (33P) terminal No. 22 and body ground after 2 seconds.
Is there battery voltage?
YES -
Go to step 27.
NO -
Replace the driver's under-dash fuse/relay box; USA model Driver's Under-Dash Fuse/Relay Box (Driver's MICU) Removal and Installation (USA Models), Canada model Driver's Under-Dash Fuse/Relay Box (Driver's MICU) Removal and Installation (Canada Models).
27. Turn the ignition switch to LOCK (0).
28. Remove the rear seat cushion Rear Seat Removal / Installation.
29. Remove the access panel from the floor Fuel Tank Unit Removal/Installation.
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 -
Go to step 35.
NO -
Go to step 31.
31. Turn the ignition switch to LOCK (0).
32. Remove PGM-FI main relay 2.
33. Connect PGM-FI main relay 2 4P connector terminals No. 1 and No. 2 with a jumper wire.
34. 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 an open in the wire between the driver's under-dash fuse/relay box (D10) and the fuel tank unit4Pconnector.
- If the wire is OK, replace the driver's under-dash fuse/relay box; USA model Driver's Under-Dash Fuse/Relay Box (Driver's MICU) Removal and Installation (USA Models), Canada model Driver's Under-Dash Fuse/Relay Box (Driver's MICU) Removal and Installation (Canada Models).
35. Turn the ignition switch to LOCK (0).
36. 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 an open in the wire between the fuel tank unit 4P connector and G603.