Honda Civic. Manual — part 689

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
G601; 4-door (see CONNECTOR TO HARNESS INDEX ), 2-door (see
CONNECTOR TO HARNESS INDEX ).

FUEL PRESSURE RELIEVING

Before disconnecting fuel lines or hoses, relieve pressure from the system by
disabling the fuel pump and disconnecting the fuel tube/quick connect fitting in the
engine compartment.

WITH THE HDS

1. Make sure you have the anti-theft code for the audio system or the navigation

system (if equipped).

2. Turn the ignition switch OFF.
3. Connect the HDS to the data link connector (DLC) (A) located under the

driver's side of the dashboard.

Fig. 25: Connecting HDS To DLC
Courtesy of AMERICAN HONDA MOTOR CO., INC.

4. Turn the ignition switch ON (II).
5. Make sure the HDS communicates with the ECM/PCM and other vehicle

systems. If it doesn't, go to the DLC circuit troubleshooting (see DLC
CIRCUIT TROUBLESHOOTING ).

2008 Honda Civic GX

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

6. Turn the ignition switch OFF.
7. Remove the fuel fill cap to relieve the pressure in the fuel tank.
8. Turn the ignition switch ON (II).
9. From the INSPECTION MENU of the HDS, select Fuel Pump OFF, then start

the engine, and let it idle until it stalls.

10. Turn the ignition switch OFF.
11. Disconnect the negative cable from the battery.
12. Remove the quick-connect fitting cover (A).

Fig. 26: Removing Quick-Connect Fitting Cover
Courtesy of AMERICAN HONDA MOTOR CO., INC.

13. Check the fuel quick-connect fitting for dirt, and clean it if needed.
14. Place a rag or shop towel over the quick-connect fitting (A).

NOTE:

Do not allow the engine to idle above 1,000 rpm or
the ECM/PCM will continue to operate the fuel
pump.

A DTC or a Temporary DTC may be set during this
procedure. Check for DTCs, and clear them as
needed (see HDS CLEAR COMMAND ).

2008 Honda Civic GX

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

Fig. 27: Placing Rag Or Shop Towel Over Quick-Connect Fitting Cover
Courtesy of AMERICAN HONDA MOTOR CO., INC.

15. Disconnect the quick-connect fitting (A): Hold the connector (B) with one

hand, and squeeze the retainer tabs (C) with the other hand to release them
from the locking tabs (D). Pull the connector off.

NOTE:

Be careful not to damage the line (E) or other parts.

Do not use tools.

If the connector does not move, keep the retainer
tabs pressed down, and alternately pull and push
the connector until it comes off easily.

Do not remove the retainer from the line; once
removed, the retainer must be replaced with a new
one.

Fig. 28: Disconnecting Quick-Connect Fitting
Courtesy of AMERICAN HONDA MOTOR CO., INC.

2008 Honda Civic GX

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

16. After disconnecting the quick-connect fitting, check it for dirt or damage (see

step 4 in FUEL LINE/QUICK-CONNECT FITTING REMOVAL ).

17. Reconnect the negative cable to the battery, then do this:
18. Enter the anti-theft code for the audio system or the navigation system (if

equipped), then enter the audio presets. Set the clock ( on vehicles without
navigation).

WITHOUT THE HDS

1. Make sure you have the anti-theft code for the audio system or the navigation

system (if equipped).

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.

Fig. 29: Removing PGM-FI Main Relay (Fuel Pump)
Courtesy of AMERICAN HONDA MOTOR CO., INC.

3. Reinstall the under-dash fuse/relay box.
4. Start the engine, and let it idle until it stalls.

5. Turn the ignition switch OFF.
6. Remove the fuel fill cap.

NOTE:

If any DTCs are stored, clear and ignore them.

2008 Honda Civic GX

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