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 on. If the fuel pump does not make noise, do this:

1. Turn the ignition switch to LOCK (0).
2. Open the fuse access panel (A), then remove PGM-FI main relay 2 (B) from the under-dash fuse/relay box.
   Fig 1: Identifying Fuse Access Panel & PGM-FI MAIN Relay

   Courtesy of AMERICAN HONDA MOTOR CO., INC.
3. Turn the ignition switch to ON (II).
4. 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  5.

   NO:  Test PGM-FI main relay 1 (see POWER RELAY TEST ). If the relay is OK, replace the under-dash fuse/relay box (see REMOVAL AND INSTALLATION ).

   Fig 2: Checking Voltage Between PGM-FI Main Relay 2 4P Connector Terminal No. 4 & Body Ground

   Courtesy of AMERICAN HONDA MOTOR CO., INC.
5. Measure the voltage between PGM-FI main relay 2 4P connector terminal No. 1 and body ground.

   Is there battery voltage? 

   YES:  Go to step  6

   NO: 

   • Check the No. 20 FUEL PUMP (15 A) fuse in the under-dash fuse/relay box.
   • If the fuse is OK, replace the under-dash fuse/relay box (see REMOVAL AND INSTALLATION ).
   Fig 3: Checking Voltage Between PGM-FI Main Relay 2 4P Connector Terminal No. 1 & Body Ground
   Courtesy of AMERICAN HONDA MOTOR CO., INC.
6. Turn the ignition switch to LOCK (0).
7. Connect PGM-FI main relay 2 4P connector terminal No. 3 to body ground with a jumper wire.
   Fig 4: Connecting PGM-FI Main Relay 2 4P Connector Terminal No. 3 To Body Ground With Jumper Wire

   Courtesy of AMERICAN HONDA MOTOR CO., INC.
8. Jump the SCS line with the HDS.
9. Disconnect ECM/PCM connector A (49P).
10. Check for continuity between body ground and ECM/PCM connector terminal A16.

    Is there continuity? 

    YES:  Go to step  11.

    NO:  Repair open in the wire between PGM-FI main relay 2 and the ECM/PCM (A16).

    Fig 5: Checking Continuity Between Body Ground & ECM/PCM Connector Terminal A16

    Courtesy of AMERICAN HONDA MOTOR CO., INC.
11. Reinstall PGM-FI main relay 2.
12. Connect ECM/PCM connector terminal A7 to body ground with a jumper wire.
    Fig 6: Connecting ECM/PCM Connector Terminal A7 To Body Ground With Jumper Wire

    Courtesy of AMERICAN HONDA MOTOR CO., INC.
13. Turn the ignition switch to ON (II).
14. Measure the voltage between ECM/PCM connector terminal A16 and body ground.

    Is there battery voltage? 

    YES:  Go to step  15.

    NO: 

    • Repair open in the wire between the under-dash fuse/relay box and the ECM/PCM (A7, A16).
    • If the wires are OK, replace PGM-FI main relay 2 (see POWER RELAY TEST ).
    Fig 7: Checking Voltage Between ECM/PCM Connector Terminal A16 & Body Ground
    Courtesy of AMERICAN HONDA MOTOR CO., INC.
15. Turn the ignition switch to LOCK (0).
16. Reconnect ECM/PCM connector A (49P).
17. Turn the ignition switch to ON (II), and measure the voltage between under-dash fuse/relay box connector B (36P) terminal No. 32 and body ground within 2 seconds.

    Is there battery voltage? 

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

    NO:  Turn the ignition switch to LOCK (0), then go to step  18.

    Fig 8: Checking Voltage Between Under-Dash Fuse/Relay Box Connector B (36P) Terminal No. 32 & Body Ground

    Courtesy of AMERICAN HONDA MOTOR CO., INC.
18. Turn the ignition switch to ON (II), and measure the voltage between under-dash fuse/relay box connector B (36P) terminal No. 32 and body ground after 2 seconds.

    Is there battery voltage? 

    YES:  Go to step  19.

    NO:  Replace the under-dash fuse/relay box (see REMOVAL AND INSTALLATION ).

    Fig 9: Checking Voltage Between Under-Dash Fuse/Relay Box Connector B (36P) Terminal No. 32 & Body Ground

    Courtesy of AMERICAN HONDA MOTOR CO., INC.
19. Turn the ignition switch to LOCK (0).
20. Remove the center console (see CENTER CONSOLE REMOVAL/INSTALLATION ).
21. Remove the parking brake lever, then remove the access panel from the floor (see REMOVAL  ).
22. 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  27.

    NO:  Go to step  23.

    Fig 10: Checking Voltage Between Fuel Tank Unit 4P Connector Terminal No. 2 & Body Ground

    Courtesy of AMERICAN HONDA MOTOR CO., INC.
23. Turn the ignition switch to LOCK (0).
24. Remove PGM-FI main relay 2.
25. Connect PGM-FI main relay 2 4P connector terminals No. 1 and No. 2 with a jumper wire.
    Fig 11: Connecting PGM-FI Main Relay 2 4P Connector Terminals No. 1 & No. 2 With Jumper Wire

    Courtesy of AMERICAN HONDA MOTOR CO., INC.
26. 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 open in the wire between PGM-FI main relay 2 and the fuel tank unit 4P connector.

    Fig 12: Checking Voltage Between Fuel Tank Unit 4P Connector Terminal No. 2 & Body Ground

    Courtesy of AMERICAN HONDA MOTOR CO., INC.
27. Turn the ignition switch to LOCK (0).
28. 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 G502 (see CONNECTOR TO HARNESS INDEX ).

    Fig 13: Checking Continuity Between Fuel Tank Unit 4P Connector Terminal No. 4 & Body Ground

    Courtesy of AMERICAN HONDA MOTOR CO., INC.