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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 PGM-FI main relay 2 (FUEL PUMP) (A).
    Fig 1: Removing PGM-FI Main Relay 2 (Fuel Pump)
    G03693227Courtesy of AMERICAN HONDA MOTOR CO., INC.
  3. Turn the ignition switch ON (II).
  4. Measure voltage between PGM-FI main relay 2 (FUEL PUMP) 4P connector terminal No. 4 and body ground.
    Fig 2: Measuring Voltage Between PGM-FI Main Relay 2 4P Connector Terminal No 4 And Body Ground
    G03693228Courtesy of AMERICAN HONDA MOTOR CO., INC.

    Is there battery voltage? 

    1. YES -  Go to step 5.
    2. 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) 4P connector terminal No. 1 and body ground.
    Fig 3: Measuring Voltage Between PGM-FI Main Relay 2 4P Connector Terminal No 1 And Body Ground
    G03693229Courtesy of AMERICAN HONDA MOTOR CO., INC.

    Is there battery voltage? 

    1. YES -  Go to step 6.
    2. NO - 
      • Replace the No. 2 FUEL PUMP (15 A) fuse in the under-dash fuse/relay box.
      • If needed, replace the under-dash fuse/relay box.
  6. Turn the ignition switch OFF.
  7. Connect PGM-FI main relay 2 (FUEL PUMP) 4P connector terminal No. 3 to body ground with a jumper wire.
    Fig 4: Connecting PGM-FI Main Relay 2 (Fuel Pump) 4P Connector Terminal No 3 To Body Ground
    G03693230Courtesy of AMERICAN HONDA MOTOR CO., INC.
  8. Turn the ignition switch OFF.
  9. Jump the SCS line with the HDS.
  10. Disconnect ECM connector E (31P).
  11. Check for continuity between body ground and ECM connector terminal E17.
    Fig 5: Checking Continuity Between Body Ground And ECM Connector Terminal E17
    G03693231Courtesy of AMERICAN HONDA MOTOR CO., INC.

    Is there continuity? 

    1. YES -  Go to step 12.
    2. NO -  Repair open in the wire between PGM-FI main relay 2 (FUEL PUMP) and the ECM (E17).
  12. Reinstall PGM-FI main relay 2 (FUEL PUMP).
  13. Connect ECM connector terminal E7 to body ground with a jumper wire.
    Fig 6: Connecting ECM Connector Terminal E7 To Body Ground With Jumper Wire
    G03693232Courtesy of AMERICAN HONDA MOTOR CO., INC.
  14. Turn the ignition switch ON (II).
  15. Measure voltage between ECM connector terminal E17 and body ground.
    Fig 7: Measuring Voltage Between ECM Connector Terminal E17 And Body Ground
    G03693233Courtesy of AMERICAN HONDA MOTOR CO., INC.

    Is there battery voltage? 

    1. YES -  Go to step 16.
    2. NO -  Replace PGM-FI main relay 2 (FUEL PUMP).
  16. Turn the ignition switch OFF.
  17. Reconnect ECM connector E (31P), and disconnect the jumper wire.
  18. Open the SCS line with the HDS.
  19. Turn the ignition switch OFF.
  20. Turn the ignition switch ON (II), and measure voltage between ECM connector terminal E17 and body ground within 2 seconds.
    Fig 8: Measuring Voltage Between ECM Connector Terminal E17 And Body Ground
    G03693234Courtesy of AMERICAN HONDA MOTOR CO., INC.

    Is there battery voltage? 

    1. YES -  Update the ECM if it does not have the latest software, or substitute a known-good ECM (see UPDATING THE ECM ), then recheck. If the symptom/ indication goes away with a known-good ECM, replace the original ECM (see ECM REPLACEMENT ), then go to step 21.
    2. NO -  If needed, replace the under-dash fuse/relay box, then go to step 21.
  21. Turn the ignition switch OFF.
  22. Remove the rear tray (see TRIM REMOVAL/INSTALLATION - REAR TRAY AREA ).
  23. Remove the access panel from the floor (see FUEL TANK UNIT REMOVAL/INSTALLATION  ).
  24. Turn the ignition switch ON (II), and measure voltage between fuel pump 5P connector terminal No. 5 and body ground within 2 seconds.
    Fig 9: Measuring Voltage Between Fuel Pump 5P Connector Terminal No 5 And Body Ground
    G03693235Courtesy of AMERICAN HONDA MOTOR CO., INC.

    Is there battery voltage? 

    1. YES -  Go to step  29.
    2. NO -  Go to step 25.
  25. Turn the ignition switch OFF.
  26. Remove PGM-FI main relay 2 (FUEL PUMP).
  27. Connect PGM-FI main relay 2 (FUEL PUMP) 4P connector terminals No. 1 and No. 2 with a jumper wire.
    Fig 10: Connecting PGM-FI Main Relay 2 (Fuel Pump) 4P Connector Terminals No 1 And No 2
    G03693236Courtesy of AMERICAN HONDA MOTOR CO., INC.
  28. Turn the ignition switch ON (II), and measure voltage between fuel pump 5P connector terminal No. 5 and body ground.
    Fig 11: Measuring Voltage Between Fuel Pump 5P Connector Terminal No 5 And Body Ground
    G03693237Courtesy of AMERICAN HONDA MOTOR CO., INC.

    Is there battery voltage? 

    1. YES -  Replace PGM-FI main relay 2 (FUEL PUMP).
    2. NO -  Repair open in the wire between PGM-FI main relay 2 (FUEL PUMP) and the fuel pump 5P connector.
  29. Turn the ignition switch OFF.
  30. Check for continuity between fuel pump 5P connector terminal No. 4 and body ground.
    Fig 12: Checking Continuity Between Fuel Pump 5P Connector Terminal No 4 And Body Ground
    G03693238Courtesy of AMERICAN HONDA MOTOR CO., INC.

    Is there continuity? 

    1. YES -  Replace the fuel pump.
    2. NO -  Repair open in the wire between the fuel pump 5P connector and G603.
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