Honda Civic. Manual — part 660

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

27. Reconnect all connectors.
28. Update the PCM if it does not have the latest software (see UPDATING THE

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

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

Is DTC P0183 indicated?

YES -Check for poor connections or loose terminals at the fuel temperature
sensor and the PCM. If the PCM was updated, substitute a known-good PCM
(see SUBSTITUTING THE PCM ), then recheck. If the PCM was
substituted, go to step 1.

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

DTC P0191: FUEL RAIL PRESSURE SENSOR CIRCUIT RANGE/PERFORMANCE PROBLEM

1. Turn the ignition switch OFF.
2. Check for a loose or damaged fuel pressure regulator P1 vacuum line.

Is the line OK?

YES -Go to step 3.

NO -Reconnect or repair the fuel pressure regulator P1 vacuum line, then go to
step 21.

NOTE:

Before you troubleshoot, record all freeze data and any on-
board snapshot, and review the general troubleshooting
information (see GENERAL TROUBLESHOOTING
INFORMATION ).

2008 Honda Civic GX

2006-08 ENGINE PERFORMANCE Fuel Supply System - Civic GX

3. Check the fuel system for any leaking parts (see LEAK INSPECTION ).

Are any parts leaking?

YES -Replace the leaking part(s), then go to step 21.

NO -Go to step 4.

4. Start the engine. Hold the engine speed at 3,000 rpm without load (in Park or

neutral) until the radiator fan comes on, then let it idle.

5. Test-drive the vehicle for several minutes in the range of these recorded on-

board snapshot parameters:

ENGINE SPEED

MAP SENSOR

6. Monitor the OBD STATUS for DTC P0191 in the DTCs MENU with the

HDS.

Does the screen indicate FAILED?

YES -Go to step 7.

NO -If the screen indicates PASSED, intermittent failure, the system is OK at
this time. Check for poor connections or loose terminals at the fuel rail
pressure sensor and the PCM. If the screen indicates EXECUTING, keep
driving until a result comes on. If the screen indicates OUT OF CONDITION,
go to step 4 and recheck.

7. Start the engine. Hold the engine speed at 3,000 rpm without load (in Park or

neutral) until the radiator fan comes on, then let it idle.

8. Snap the throttle to an engine speed of 3,000 rpm or more.
9. Check the FUEL RAIL PRESSURE SENSOR in the DATA LIST with the

HDS while snapping the throttle.

Does the reading change 4 kPa (0.58 psi, 0.04 kgf/cm

2

) or more?

YES -Go to step 10.

2008 Honda Civic GX

2006-08 ENGINE PERFORMANCE Fuel Supply System - Civic GX

NO -Replace the fuel rail pressure sensor (see FUEL PRESSURE SWITCH
REPLACEMENT ), then go to step 19.

10. Check the FUEL RAIL PRESSURE SENSOR in the DATA LIST with the

HDS at idle.

Is about 204-326 kPa (29.58-47.3 psi, 2.08-3.32 kgf/cm

2

) indicated?

YES -Go to step 16.

NO -Go to step 11.

11. Turn the ignition switch OFF.
12. Remove the fuel rail pressure sensor (see FUEL PRESSURE SWITCH

REPLACEMENT ).

13. Reconnect the fuel rail pressure sensor 3P connector to the sensor.
14. Turn the ignition switch ON (II).
15. Compare the value of the BARO SENSOR and the FUEL RAIL PRESSURE

SENSOR in the DATA LIST with the HDS.

Does the reading differ 22.3 kPa (3.23 psi, 0.23 kgf/cm

2

) or more?

YES -Replace the fuel rail pressure sensor (see FUEL PRESSURE SWITCH
REPLACEMENT ), then go to step 19.

NO -Replace the fuel pressure regulator P1 (see FUEL PRESSURE
REGULATOR P1 REPLACEMENT ), then go to step 19.

16. Check the MAP SENSOR in the DATA LIST with the HDS.

Is about 53.2 kPa (15.7 in.Hg, 399 mmHg), or 1.59 V or more indicated?

YES -Go to step 17.

NO -Replace the MAP sensor, refer to the MAP SENSOR
REPLACEMENT , then go to step 19.

2008 Honda Civic GX

2006-08 ENGINE PERFORMANCE Fuel Supply System - Civic GX

17. Start the engine.
18. Check the MAP SENSOR in the DATA LIST with the HDS while snapping

the throttle to fuel cut engine speed.

Is about 36.9 kPa (10.9 in.Hg, 277 mmHg), or 1.51 V or less indicated?

YES -Check for poor connections or loose terminals at the fuel rail pressure
sensor and the PCM. Also check for a loose or damage fuel pressure regulator
P1 vacuum line. Then go to step 19.

NO -Replace the MAP sensor, refer to the MAP SENSOR
REPLACEMENT , then go to step 19.

19. Turn the ignition switch OFF.
20. Reconnect all connectors.
21. Turn the ignition switch ON (II).
22. Reset the PCM with the HDS.
23. Do the PCM idle learn procedure, refer to the ECM/PCM IDLE LEARN

PROCEDURE .

24. Test-drive the vehicle for several minutes in the range of these recorded on-

board snapshot parameters:

ENGINE SPEED

MAP SENSOR

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

Is DTC P0191 indicated?

YES -Check for poor connections or loose terminals at the fuel rail pressure
sensor and the PCM, then go to step 1.

NO -Go to step 26.

26. Monitor the OBD STATUS for DTC P0191 in the DTCs MENU with the

HDS.

2008 Honda Civic GX

2006-08 ENGINE PERFORMANCE Fuel Supply System - Civic GX