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:

Turn the ignition switch to LOCK (0).
Remove PGM-FI main relay 2 (A) from the auxiliary under-hood fuse/relay box (to the left of the 12 volt battery).

Fig 1: Identifying PGM-FI Main Relay 2
Courtesy of AMERICAN HONDA MOTOR CO., INC.
Turn the ignition switch to ON (II).
Measure the voltage between PGM-FI main relay 2 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
Courtesy of AMERICAN HONDA MOTOR CO., INC.

Is there battery voltage?

YES -Go to step 6.

NO -Go to step 5.
Measure the voltage between under-dash fuse/relay box B connector (36P) terminal No. 8 and body ground.

Fig 3: Measuring Voltage Between Under-Dash Fuse/Relay Box B Connector (36P) Terminal No. 8 And Body Ground
Courtesy of AMERICAN HONDA MOTOR CO., INC.

Is there battery voltage?

YES -Repair an open in the wire between PGM-FI main relay 2 and the under-dash fuse/relay box.

NO -
- Replace PGM-FI main relay 1.
- If needed, replace the under-dash fuse/relay box (USA model) (see REMOVAL AND INSTALLATION ), (Canada model) (see CANADA MODEL ).
Measure the voltage between PGM-FI main relay 2 4P connector terminal No. 1 and body ground.

Fig 4: Measuring Voltage Between PGM-FI Main Relay 2 4P Connector Terminal No. 1 And Body Ground
Courtesy of AMERICAN HONDA MOTOR CO., INC.

Is there battery voltage?

YES -Go to step 8

NO -Go to step 7.
Measure the voltage between under-dash fuse/relay box B connector (36P) terminal No. 14 and body ground.

Fig 5: Measuring Voltage Between Under-Dash Fuse/Relay Box B Connector (36P) Terminal No. 14 And Body Ground
Courtesy of AMERICAN HONDA MOTOR CO., INC.

Is there battery voltage?

YES -Repair an open in the wire between PGM-FI main relay 2 and the under-dash fuse/relay box.

NO -
- Check the No. 20 FUEL PUMP (15A) fuse in the under dash fuse/relay box.
- If the fuse is OK, replace the under-dash fuse/relay box (USA model) (see REMOVAL AND INSTALLATION ), (Canada model) (see CANADA MODEL ).
Turn the ignition switch to LOCK (0).
Connect PGM-FI main relay 2 4P connector terminal No. 3 to body ground with a jumper wire.

Fig 6: Connecting PGM-FI Main Relay 2 4P Connector Terminal No. 3 To Body Ground Using Jumper Wire
Courtesy of AMERICAN HONDA MOTOR CO., INC.
Jump the SCS line with the HDS.
Disconnect PCM connector A (49P).
Check for continuity between PCM connector terminal A30 and body ground.

Fig 7: Checking Continuity Between PCM Connector Terminal A30 And Body Ground
Courtesy of AMERICAN HONDA MOTOR CO., INC.

Is there continuity?

YES -Go to step 13.

NO -Repair an open in the wire between PGM-FI main relay 2 and the PCM (A30).
Reinstall PGM-FI main relay 2.
Connect PCM connector terminal A7 to body ground with a jumper wire.

Fig 8: Connecting PCM Connector Terminal A7 To Body Ground Using Jumper Wire
Courtesy of AMERICAN HONDA MOTOR CO., INC.
Turn the ignition switch to ON (II).
Measure the voltage between PCM connector terminal A30 and body ground.

Fig 9: Measuring Voltage Between PCM Connector Terminal A30 And Body Ground
Courtesy of AMERICAN HONDA MOTOR CO., INC.

Is there battery voltage?

YES -Go to step 17.

NO -Replace PGM-FI main relay 2.
Turn the ignition switch to LOCK (0).
Remove the rear seat cushion (see REAR SEAT REMOVAL/INSTALLATION ).
Remove the access panel from the floor (see step 3).
Disconnect the fuel tank unit 4P connector.
Reconnect PCM connector A (49P).
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.

Fig 10: Measuring Voltage Between Fuel Tank Unit 4P Connector Terminal No. 2 And Body Ground
Courtesy of AMERICAN HONDA MOTOR CO., INC.

Is there battery voltage?

YES -Go to step 23.

NO -Go to step 25.
Turn the ignition switch to LOCK (0).
Check for continuity between fuel tank unit 4P connector terminal No. 4 and body ground.

Fig 11: Checking Continuity Between Fuel Tank Unit 4P Connector Terminal No. 4 And Body Ground
Courtesy of AMERICAN HONDA MOTOR CO., INC.

Is there continuity?

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

NO -Repair an open in the wire between the fuel tank unit and G602 (see CONNECTOR TO FUSE/RELAY BOX INDEX ).
Turn the ignition switch to LOCK (0).
Remove PGM-FI main relay 2 (A) from the auxiliary under-hood fuse/relay box (to the left of the 12 volt battery).

Fig 12: Identifying PGM-FI Main Relay 2
Courtesy of AMERICAN HONDA MOTOR CO., INC.
Connect PGM-FI main relay 2 4P connector terminals No. 1 and No. 2 with a jumper wire.

Fig 13: Connecting PGM-FI Main Relay 2 4P Connector Terminals No. 1 And No. 2 Using Jumper Wire
Courtesy of AMERICAN HONDA MOTOR CO., INC.
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.

Fig 14: Measuring Voltage Between Fuel Tank Unit 4P Connector Terminal No. 2 And Body Ground
Courtesy of AMERICAN HONDA MOTOR CO., INC.

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 and the PCM was updated, troubleshooting is complete. If the symptom/indication goes away and the PCM was substituted, replace the original PCM (see PCM REPLACEMENT ).

NO -Repair an open in the wire between the fuel tank unit and PGM-FI main relay 2.