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 first turned on. If the fuel pump does not make noise, check as follows:

1. Turn the ignition switch OFF.
2. Remove the glove box (see GLOVE BOX REMOVAL/INSTALLATION ), then remove PGM-FI main relay 2 (A).
   Fig 1: Removing PGM-FI Main Relay 2

   Courtesy of AMERICAN HONDA MOTOR CO., INC.
3. Turn the ignition switch ON (II).
4. Measure voltage between PGM-FI main relay 2 5P connector terminal No. 5 and body ground.
   Fig 2: Measuring Voltage Between PGM-FI Main Relay 2 5P Connector Terminal No. 5 And Body Ground

   Courtesy of AMERICAN HONDA MOTOR CO., INC.

   Is there battery voltage? 

   YES:  Go to step 5.

   NO:  Repair open in the wire between PGM-FI main relay 1 and PGM-FI main relay 2.

5. Measure voltage between PGM-FI main relay 2 5P connector terminal No. 1 and body ground.
   Fig 3: Measuring Voltage Between PGM-FI Main Relay 2 5P Connector Terminal No. 1 And Body Ground

   Courtesy of AMERICAN HONDA MOTOR CO., INC.

   Is there battery voltage? 

   YES:  Go to step 6.

   NO:  Repair open in the wire between the under-dash fuse/relay box and PGM-FI main relay 2.

6. Turn the ignition switch OFF.
7. Disconnect ECM connector E (31P).
8. Check for continuity between PGM-FI main relay 2 5P connector terminal No. 3 and ECM connector terminal E1.
   Fig 4: Checking For Continuity Between PGM-FI Main Relay 2 5P Connector Terminal No. 3 And ECM Connector Terminal E1

   Courtesy of AMERICAN HONDA MOTOR CO., INC.

   Is there continuity? 

   YES:  Go to step 9.

   NO:  Repair open in the wire between PGM-FI main relay 2 and ECM (E1).

9. Reinstall PGM-FI main relay 2.
10. Turn the ignition switch ON (II).
11. Measure voltage between ECM/PCM connector terminal E1 and body ground.
    Fig 5: Measuring Voltage Between ECM/PCM Connector Terminal E1 And Body Ground

    Courtesy of AMERICAN HONDA MOTOR CO., INC.

    Is there battery voltage? 

    YES:  Go to step 12.

    NO:  Replace PGM-FI main relay 2.

12. Turn the ignition switch OFF.
13. Reconnect ECM connector E (319).
14. Turn the ignition switch ON (II), and measure voltage between ECM connector terminal E1 and body ground within the first 2 seconds after the ignition switch was turned ON (II).
    Fig 6: Measuring Voltage Between ECM Connector Terminal E1 And Body Ground

    Courtesy of AMERICAN HONDA MOTOR CO., INC.

    Is there battery voltage? 

    YES:  Update the ECM if it does not have the latest software, or substitute a known-good ECM, then recheck (see ECM UPDATING AND SUBSTITUTION FOR TESTING ). If the symptom/indication goes away with a known-good ECM, replace the original ECM.

    NO:  Go to step 15.

15. Turn the ignition switch OFF.
16. Remove the rear seat cushion (see REAR SEAT REMOVAL/INSTALLATION ).
17. Remove the access panel from the floor.
18. Measure voltage between fuel pump 5P connector terminal No. 5 and body ground within the first 2 seconds after the ignition switch was turned ON (II).
    Fig 7: Measuring Voltage Between Fuel Pump 5P Connector Terminal No. 5 And Body Ground

    Courtesy of AMERICAN HONDA MOTOR CO., INC.

    Is there battery voltage? 

    YES:  Go to step  24 .

    NO:  Go to step 19.

19. Turn the ignition switch OFF.
20. Remove PGM-FI main relay 2.
21. Connect PGM-FI main relay 2 5P connector terminals No. 1 and No. 2 with a jumper wire.
    Fig 8: Connecting PGM-FI Main Relay 2 5P Connector Terminals No. 1 And No. 2 With A Jumper Wire

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22. Turn the ignition switch ON (II).
23. Measure voltage between fuel pump 5P connector terminal No. 5 and body ground.
    Fig 9: Measuring Voltage Between Fuel Pump 5P Connector Terminal No. 5 And Body Ground

    Courtesy of AMERICAN HONDA MOTOR CO., INC.

    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 pump 5P connector.

24. Turn the ignition switch OFF.
25. Check for continuity between fuel pump 5P connector terminal No. 4 and body ground.
    Fig 10: Checking For Continuity Between Fuel Pump 5P Connector Terminal No. 4 And Body Ground

    Courtesy of AMERICAN HONDA MOTOR CO., INC.

    Is there continuity? 

    YES:  Replace the fuel pump.

    NO:  Repair open in the wire between the fuel pump 5P connector and G551.