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 PGM-FI main relay 2 (FUEL PUMP) (A).
3. Turn the ignition switch ON (II).
4. Measure voltage between PGM-FI main relay 2 (FUEL PUMP) 5P connector terminal No. 5 and body ground.
Is there battery voltage?
YES - Go to step 5.
NO - Repair open in the wire between PGM-FI main relay 1 (FI MAIN) and PGM-FI main relay 2 (FUEL PUMP).*
5. Measure voltage between PGM-FI main relay 2 (FUEL PUMP) 5P connector terminal No. 1 and body ground.
Is there battery voltage?
YES - Go to step 6.
NO
- Check the No. 1 FUEL PUMP (15 A) fuse in the driver's under-dash fuse/relay box.
- Check for an open between the driver's under-dash fuse/relay box and PGM-FI main relay 2 (FUEL PUMP).
- 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) 5P connector terminal No. 3 to body ground with a jumper wire.
8. Jump the SCS line with the HDS.
9. Disconnect PCM connector A (44P).
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 A6 to body ground with jumper wire.
13. Turn the ignition switch ON (II).
14. Measure voltage between PCM connector terminal A11 and body ground.
Is there battery voltage?
YES - Go to step 15.
NO - Replace PGM-FI main relay 2 (FUEL PUMP).
15. Turn the ignition switch OFF.
16. Reconnect PCM connector A (44P).
17. Open the SCS line with the HDS.
18. Turn the ignition switch ON (II), then measure voltage between PGM-FI main relay 2 (FUEL PUMP) 5P 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 driver's side second row seat.
21. Cut the carpet at the dotted line (A). Be careful not to cut the wire harness under the carpet.
22. Remove the access panel from the floor.
23. Turn the ignition switch ON (II), then 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 28.
NO - Go to step 24.
24. Turn the ignition switch OFF.
25. Remove PGM-FI main relay 2 (FUEL PUMP).
26. Connect PGM-FI main relay 2 (FUEL PUMP) 5P connector terminals No. 1 and No. 2 with a jumper wire.
27. 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 - Replace PGM-FI main relay 2 (FUEL PUMP).
NO - Repair open in the wire between PGM-FI main relay 2 (FUEL PUMP) and fuel tank unit 5P connector.
28. Turn the ignition switch OFF.
29. 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 G601.