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. A*: The illustration shows LHD model.

4.	Turn the ignition switch ON (II).

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

PGM-FI MAIN RELAY 2 (FUEL PUMP) 4P CONNECTORTerminal side of female terminalsIGP

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. PGM-FI MAIN RELAY 2 (FUEL PUMP) 4P CONNECTORTerminal side of female terminalsIG1 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. INERTIA SWITCH 3P CONNECTORJUMPER WIREIG1 (BLK/YEL)INERTIA SWITCH (YEL/BLK)Wire side of female terminals

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.

PGM-FI MAIN RELAY 2 (FUEL PUMP) 4P CONNECTORTerminal side of female terminalsIG1

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. PGM-FI MAIN RELAY 2 (FUEL PUMP) 4P CONNECTORTerminal side of female terminalsIMOFPRJUMPER 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. ECM/PCM CONNECTOR E (31P)Wire side of female terminalsIMOFPR (WHT) 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. ECM/PCM CONNECTOR E (31P)Wire side of female terminalsMRLY (RED/BLK)JUMPER WIRE

20.	Turn the ignition switch ON (II).

21.	Measure voltage between ECM/PCM connector terminal E17 and body ground. ECM/PCM CONNECTOR E (31P)Wire side of female terminalsIMOFPR (WHT) 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.

ECM/PCM CONNECTOR E (31P)Wire side of female terminalsIMOFPR (WHT)

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. FUEL PUMP 5P CONNECTORFUEL PUMP (YEL/GRN)Wire side of female terminals 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. PGM-FI MAIN RELAY 2 (FUEL PUMP) 4P CONNECTORTerminal side of female terminalsFUEL PUMPJUMPER WIREIG1

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.

FUEL PUMP 5P CONNECTORFUEL PUMP
(YEL/GRN)Wire side of female terminals

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. FUEL PUMP 5P CONNECTORGND (BLK)Wire side of female terminals Is there continuity? YES - Replace the fuel pump.n NO - Repair open in the wire between the fuel pump 5P connector and G603.n