Honda Civic. Manual — part 686

Fig. 8: Checking Continuity Between Gauge Control Module (TACH)
Terminal No. 32 And Body Ground
Courtesy of AMERICAN HONDA MOTOR CO., INC.

Is there continuity?

YES - Go to step 14.

NO - Repair open in the wire between the gauge control module (tach) (signal
line) and the fuel gauge sending unit, then go to step 24.

14. Remove the jumper wire from the fuel tank unit 4P connector.
15. Remove the fuel tank unit (see FUEL TANK UNIT

REMOVAL/INSTALLATION ).

16. Test the fuel gauge sending unit (see FUEL GAUGE SENDING UNIT

TEST ).

Is the fuel gauge sending unit OK?

YES - Go to step 17.

NO - Replace the fuel gauge sending unit (see FUEL PUMP/FUEL GAUGE
SENDING UNIT REPLACEMENT ), then go to step 23.

17. Connect the fuel tank unit 4P connector.
18. Reconnect the gauge control module (tach) 36P connector.
19. Turn the ignition switch ON (II).
20. Clear the DTC with the HDS.

2008 Honda Civic GX

2006-08 ENGINE PERFORMANCE Fuel Supply System (R18A1) - Civic (Except Hybrid)

21. Set the float (A) to the F position.

Fig. 9: Setting Float To F Position (With Specifications)
Courtesy of AMERICAN HONDA MOTOR CO., INC.

22. Check the fuel gauge.

Does the gauge move to the full position?

YES - Go to step 32.

NO - Replace the gauge control module (tach) (see TACHOMETER ), then
go to step 23.

23. Turn the ignition switch OFF.
24. Reconnect all connectors.
25. Install the parts in the reverse order of removal.
26. Turn the ignition switch ON (II).
27. Reset the ECM/PCM with the HDS.
28. Do the ECM/PCM idle learn procedure (see ECM/PCM IDLE LEARN

PROCEDURE ).

29. Check for Temporary DTCs or DTCs with the HDS.

Is DTC P0463 indicated?

YES - Check for poor connections or loose terminals at the gauge control
module (tach) and the fuel gauge sending unit, then go to step 1.

2008 Honda Civic GX

2006-08 ENGINE PERFORMANCE Fuel Supply System (R18A1) - Civic (Except Hybrid)

NO - Troubleshooting is complete. If any other Temporary DTCs or DTCs are
indicated, go to the indicated DTC's troubleshooting.

30. Reconnect all connectors.
31. Install the parts in the reverse order of removal.
32. Update the ECM/PCM if it does not have the latest software (see UPDATING

ECM/PCM ), or substitute a known-good ECM/PCM (see SUBSTITUTING
THE ECM/PCM ).

33. Check for Temporary DTCs or DTCs with the HDS.

Is DTC P0463 indicated?

YES - Check for poor connections or loose terminals at the gauge control
module (tach) and the fuel gauge sending unit. If the ECM/PCM was updated,
substitute a known-good ECM/PCM (see SUBSTITUTING THE
ECM/PCM ), then recheck. If the ECM/PCM was substituted, go to step 1.

NO - If the ECM/PCM was updated, troubleshooting is complete. If the
ECM/PCM was substituted, replace the original ECM/PCM (see ECM/PCM
REPLACEMENT ). If any other Temporary DTCs or DTCs are indicated, go
to the indicated DTC's troubleshooting.

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. Remove the under-dash fuse/relay box (see REMOVAL AND

INSTALLATION ), then remove PGM-FI main relay 2 (FUEL PUMP) (A)
from the under-dash fuse/relay box.

2008 Honda Civic GX

2006-08 ENGINE PERFORMANCE Fuel Supply System (R18A1) - Civic (Except Hybrid)

Fig. 10: Removing PGM-FI Main Relay (Fuel Pump)
Courtesy of AMERICAN HONDA MOTOR CO., INC.

3. Reinstall the under-dash 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. 4 and body ground.

Fig. 11: Measuring Voltage Between PGM-FI Main Relay 2 (FUEL
PUMP) 4P Connector Terminal No. 4 And Body Ground
Courtesy of AMERICAN HONDA MOTOR CO., INC.

Is there battery voltage?

YES - Go to step 12.

NO - Go to step 6.

2008 Honda Civic GX

2006-08 ENGINE PERFORMANCE Fuel Supply System (R18A1) - Civic (Except Hybrid)