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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 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 PGM-FI main relay 2 (FUEL PUMP) (A) from the under-dash fuse/relay box.
    Fig 1: Identifying PGM-FI Main Relay 2 (Fuel Pump)
    G05961391Courtesy of AMERICAN HONDA MOTOR CO., INC.
  3. Turn the ignition switch to ON (II).
  4. Measure the voltage between PGM-FI main relay 2 (FUEL PUMP) 4P connector terminal No. 4 and body ground.
    Fig 2: Checking Voltage Between PGM-FI Main Relay 2 (Fuel Pump) 4P Connector Terminal No. 4 & Body Ground
    G05961392Courtesy of AMERICAN HONDA MOTOR CO., INC.

    5. Is there battery voltage? 

    YES  - Go to step  10.

    NO  - Go to step  5.

  5. Turn the ignition switch to LOCK (0).
  6. Disconnect under-hood fuse/relay box connector D (8P).
  7. Disconnect under-dash fuse/relay box connector G (21P).
  8. Connect under-dash fuse/relay box connector G (21P) terminal No. 4 to body ground with a jumper wire.
    Fig 3: Connecting Under-Dash Fuse/Relay Box Connector G (21P) Terminal No. 4 To Body Ground With Jumper Wire
    G05961393Courtesy of AMERICAN HONDA MOTOR CO., INC.
  9. Check for continuity between under-hood fuse/relay box connector D (8P) terminal No. 6 and body ground.
    Fig 4: Checking Continuity Between Under-Hood Fuse/Relay Box Connector D (8P) Terminal No. 6 & Body Ground
    G05961394Courtesy of AMERICAN HONDA MOTOR CO., INC.

    10. Is there continuity? 

    YES  - Replace PGM-FI main relay 1. ■

    NO  -

    • Repair open in the wire between the under-hood fuse/relay box and the under-dash fuse/relay box. ■
    • If the wire is OK, replace the under-hood fuse/relay box (see REMOVAL AND INSTALLATION ). ■

  10. Measure the voltage between PGM-FI main relay 2 (FUEL PUMP) 4P connector terminal No. 1 and body ground.
    Fig 5: Checking Voltage Between PGM-FI Main Relay 2 (Fuel Pump) 4P Connector Terminal No. 1 & Body Ground
    G05961395Courtesy of AMERICAN HONDA MOTOR CO., INC.

    11. Is there battery voltage? 

    YES  - Go to step  11.

    NO  -

    • Check the No. 2 FUEL PUMP (15A) fuse in the under-dash fuse/relay box. ■
    • If needed, replace the under-dash fuse/relay box (see REMOVAL AND INSTALLATION ). ■

  11. Turn the ignition switch to LOCK (0).
  12. Connect PGM-FI main relay 2 (FUEL PUMP) 4P connector terminal No. 3 to body ground with a jumper wire.
    Fig 6: Connecting PGM-FI Main Relay 2 (Fuel Pump) 4P Connector Terminal No. 3 To Body Ground With Jumper Wire
    G05961396Courtesy of AMERICAN HONDA MOTOR CO., INC.
  13. Jump the SCS line with the HDS.
  14. Disconnect PCM connector A (49P).
  15. Check for continuity between body ground and PCM connector terminal A11.
    Fig 7: Checking Continuity Between Body Ground & PCM Connector Terminal A11
    G05961397Courtesy of AMERICAN HONDA MOTOR CO., INC.

    16. Is there continuity? 

    YES  - Reinstall the PGM-FI main relay 2, then go to step  16.

    NO  - Repair open in the wire between PGM-FI main relay 2 (FUEL PUMP) and the PCM (A11). ■

  16. Connect PCM connector terminal A6 to body ground with a jumper wire.
    Fig 8: Connecting PCM Connector Terminal A6 To Body Ground With Jumper Wire
    G05961398Courtesy of AMERICAN HONDA MOTOR CO., INC.
  17. Turn the ignition switch to ON (II).
  18. Measure the voltage between PCM connector terminal A11 and body ground.
    Fig 9: Checking Voltage Between PCM Connector Terminal A11 & Body Ground
    G05961399Courtesy of AMERICAN HONDA MOTOR CO., INC.

    19. Is there battery voltage? 

    YES  - Go to step  19.

    NO  - Replace PGM-FI main relay 2 (FUEL PUMP). ■

  19. Turn the ignition switch to LOCK (0).
  20. Reconnect PCM connector A (49P).
  21. Turn the ignition switch to ON (II), and measure voltage between under-dash fuse/relay box connector F (34P) terminal No. 10 and body ground within 2 seconds.
    Fig 10: Checking Voltage Between Under-Dash Fuse/Relay Box Connector F (34P) Terminal No. 10 & Body Ground
    G05961400Courtesy of AMERICAN HONDA MOTOR CO., INC.

    22. Is there battery voltage? 

    YES  - Update the PCM if it does not have the latest software (see PCM UPDATE ), or substitute a known-good PCM (see SUBSTITUTING THE PCM ), then recheck. If the symptom/indication goes away with a known-good PCM, replace the original PCM (see PCM REPLACEMENT ). ■

    NO  - Go to step  22.

  22. Turn the ignition switch to ON (II), and measure voltage between under-dash fuse/relay box connector F (34P) terminal No. 10 and body ground after 2 seconds.
    Fig 11: Checking Voltage Between Under-Dash Fuse/Relay Box Connector F (34P) Terminal No. 10 & Body Ground
    G05961401Courtesy of AMERICAN HONDA MOTOR CO., INC.

    23. Is there battery voltage? 

    YES  - Go to step  23.

    NO  - If needed, replace the under-dash fuse/relay box (see REMOVAL AND INSTALLATION ). ■

  23. Turn the ignition switch to LOCK (0).
  24. Remove the second row seat (see SECOND ROW SEAT REMOVAL/INSTALLATION ).
  25. Pull the carpet back out of the way, then remove the access panel from the floor (see FUEL TANK UNIT REMOVAL/INSTALLATION  ).
  26. Turn the ignition switch to ON (II), and measure voltage between fuel tank unit 4P connector terminal No. 2 and body ground within 2 seconds.
    Fig 12: Checking Voltage Between Fuel Tank Unit 4P Connector Terminal No. 2 & Body Ground
    G05961402Courtesy of AMERICAN HONDA MOTOR CO., INC.

    27. Is there battery voltage? 

    YES  - Go to step  31.

    NO  - Go to step  27.

  27. Turn the ignition switch to LOCK (0).
  28. Remove PGM-FI main relay 2 (FUEL PUMP) (A) from the under-dash fuse/relay box.
    Fig 13: Identifying PGM-FI Main Relay 2 (Fuel Pump)
    G05961403Courtesy of AMERICAN HONDA MOTOR CO., INC.
  29. Connect PGM-FI main relay 2 (FUEL PUMP) 4P connector terminals No. 1 and No. 2 with a jumper wire.
    Fig 14: Connecting PGM-FI Main Relay 2 (Fuel Pump) 4P Connector Terminals No. 1 & No. 2 With Jumper Wire
    G05961404Courtesy of AMERICAN HONDA MOTOR CO., INC.
  30. Turn the ignition switch to ON (II), and measure voltage between fuel tank unit 4P connector terminal No. 2 and body ground within 2 seconds.
    Fig 15: Checking Voltage Between Fuel Tank Unit 4P Connector Terminal No. 2 & Body Ground
    G05961405Courtesy of AMERICAN HONDA MOTOR CO., INC.

    31. 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 the fuel tank unit 4P connector. ■

  31. Turn the ignition switch to LOCK (0).
  32. Check for continuity between fuel tank unit 4P connector terminal No. 4 and body ground.

    Is there continuity? 

    YES  - Replace the fuel pump (see FUEL PUMP/FUEL GAUGE SENDING UNIT REPLACEMENT  ). ■

    NO  - Repair open in the wire between the fuel tank unit 4P connector and G503. ■

    Fig 16: Checking Continuity Between Fuel Tank Unit 4P Connector Terminal No. 4 & Body Ground
    G05961406Courtesy of AMERICAN HONDA MOTOR CO., INC.
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