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.Press the inertia switch button.

3.Remove the kick panel, then remove the PGM-FI main relay 2 (FUEL PUMP) (A) from the under-hood fuse/relay box.

4.Turn the ignition switch ON (II).

5.Measure voltage between PGM-FI main relay 2 (FUEL PUMP) 4P connector terminal No. 3 and body ground.

Is there battery voltage?


YES - Go to 6.


NO -

  • Replace the PGM-FI main relay 1 (F1 MAIN).n
  • Replace the under-dash fuse/relay box.n


6.Measure voltage between PGM-FI main relay 2 (FUEL PUMP) 4P connector terminal No. 1 and body ground.

Is there battery voltage?


YES - Go to 12.


NO - Go to 7.


7.Turn the ignition switch OFF.

8.Disconnect the inertia switch 3P connector.

9.Connect the inertia switch 3P connector terminals No. 1 and No. 3 with a jumper wire.

10.Turn the ignition switch ON (II).

11.Measure voltage between PGM-FI main relay 2 (FUEL PUMP) 4P connector terminal No. 1 and body ground.

Is there battery voltage?


YES - Replace the inertia switch.n


NO -

  • Replace the No.19 FUEL PUMP (15A) fuse in the under-dash fuse/relay box.n
  • Replace the under-dash fuse/relay box.n
  • Repair open in wires between inertia switch and under-dash fuse/relay box.n


12.Turn the ignition switch OFF.

13.Connect PGM-FI main relay 2 (FUEL PUMP) 4P connector terminal No. 4 to body ground with a jumper wire.

14.Turn the ignition switch OFF.

15. Jump the SCS line with the Honda PGM Tester or the HDS.

16.Disconnect ECM/PCM connector E (31P).

17.Check for continuity between body ground and ECM/PCM connector terminal E17.

Is there continuity?


YES - Go to 18.


NO - Repair open in the wire between PGM-FI main relay 2 (FUEL PUMP) and the ECM/PCM (E17).n


18.Reinstall PGM-FI main relay 2 (FUEL PUMP).

19.Connect the ECM/PCM connector terminal E7 to body ground with a jumper wire.

20.Turn the ignition switch ON (II).

21.Measure voltage between ECM/PCM connector terminal E17 and body ground.

Is there battery voltage?


YES - Go to 22.


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


22.Turn the ignition switch OFF.

23.Reconnect ECM/PCM connector E (31P).

24.Open the SCS line with the Honda PGM Tester or the HDS.

25. Turn the ignition switch OFF.

26.Turn the ignition switch ON (II), and measure voltage between ECM/PCM connector terminal E17 and body ground within the first 2 seconds after the ignition switch was turned on.

Is there battery voltage?


YES - Update the ECM/PCM if it does not have the latest software, or substitute a known-good ECM/PCM, then recheck. If the sympton/indication goes away with a known-good ECM/PCM, replace the original ECM/PCM.n


NO - Go to 27.


27.Turn the ignition switch OFF.

28.Remove the trunk floor.

29.Remove the access panel from the floor.

30.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.

Is there battery voltage?


YES - Go to 36.


NO - Go to 31.


31. Turn the ignition switch OFF.

32.Remove PGM-FI main relay 2 (FUEL PUMP).

33.Connect PGM-FI main relay 2 (FUEL PUMP) 4P connector terminals No. 1 and No. 2 with a jumper wire.

34.Turn the ignition switch ON (II).

35.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.

Is there battery voltage?


YES - Replace PGM-FI main relay 2 (FUEL PUMP).n


NO - Repair open in the wire between PGM-FI main relay 2 (FUEL PUMP) and the fuel pump 5P connector.n


36.Turn the ignition switch OFF.

37.Check for continuity between fuel pump 5P connector terminal No. 4 and body ground.

Is there continuity?


YES - Replace the fuel pump.n


NO - Repair open in the wire between the fuel pump 5P connector and G603.n