DTC Troubleshooting: P0300 (75) and some of P0301 (71), P0302 (72), P0303 (73), P0304 (74)

DTC P0300:  Random Misfire and Any Combination of the Following:
  
  
DTC P0302:  No. 2 Cylinder Misfire
  
  
DTC P0304:  No. 4 Cylinder Misfire

NOTE:

1.Record the following freeze data.
  • Engine speed
  • Vehicle speed
  • Throttle position
  • CLV

2.Do the DTC CLEAR in the CLEAR MENU with the HDS.

3.Start the engine with no load (in neutral), then let it idle.

4.Monitor the OBD STATUS for DTC P0301, P0302, P0303 or P0304 in the DTCs MENU with the HDS.

Is it FAILED?


YES - Go to 9.


NO - If it is PASSED, go to 5. If it is EXECUTING, keep the driving condition continually until a result comes on. If it is Out of CONDITION, wait for several minutes, and recheck.


5.Check the CYL1 MISFIRE, CYL2 MISFIRE, CYL3 MISFIRE and/or CYL4 MISFIRE in the DATA LIST for 10 minutes with the HDS.

Does CYL1 MISFIRE, CYL2 MISFIRE, CYL3 MISFIRE and/or CYL4 MISFIRE show misfire counts?


YES - Go to 9.


NO - Go to 6.


6.Test-drive the vehicle for several minutes in the range of the recorded freeze data.

7.Monitor the OBD STATUS for DTC P0301, P0302, P0303 or P0304 in the DTCs MENU with the HDS.

Is it FAILED?


YES - Go to 9.


NO - If it is PASSED, go to 8. If it is EXECUTING, keep the driving condition continually until a result comes on. If it is Out of CONDITION, go to 6 and recheck.

8.Check the CYL1 MISFIRE, CYL2 MISFIRE, CYL3 MISFIRE and/or CYL4 MISFIRE in the DATA LIST for 10 minutes with the HDS.

Does CYL1 MISFIRE, CYL2 MISFIRE, CYL3 MISFIRE and/or CYL4 MISFIRE show misfire counts?


YES - Go to 9.


NO - Intermittent failure, system is OK at this time.n


9.Turn the ignition switch OFF.

10.Check fuel quality.

Is the quality good?


YES - Go to 11.


NO - Drain the fuel from the fuel tank and fill with known-good fuel, then go to 15.


11.Inspect the spark plugs.
If the spark plugs are fouled or worn, replace them.

12.Test-drive the vehicle for several minutes in the range of the recorded freeze data.

13.Check the CYL1 MISFIRE, CYL2 MISFIRE, CYL3 MISFIRE and/or CYL4 MISFIRE in the DATA LIST for 10 minutes with the HDS.

Does CYL1 MISFIRE, CYL2 MISFIRE, CYL3 MISFIRE and/or CYL4 MISFIRE show misfire counts?


YES - Go to 14.


NO - Go to 15.

14.Check the fuel pressure.

Is the fuel pressure OK?


YES - Go to 15.


NO -


15.Turn the ignition switch ON (II).

16.Do the ECM RESET in the CLEAR MENU with the HDS.

17.Do the ETCS learn procedure.

18.Test-drive the vehicle for several minutes in the range of the recorded freeze data.

19.Check for Temporary DTCs or DTCs in the DTCs MENU with the HDS.

Are any Temporary DTCs or DTCs indicated?


YES - If DTC P0300, P0301, P0302, P0303 or P0304 is indicated, check for poor connections or loose terminals at the ignition coil, the injector, and the ECM, then go to troubleshooting DTC P0301, P0302, P0303 or P0304. If any other Temporary DTCs or DTCs are indicated, go to the indicated DTC troubleshooting.


NO - Go to 20.


20.Monitor the OBD STATUS for DTC P0301, P0302, P0303 or P0304 in the DTCs MENU with the HDS.

Is it PASSED?


YES - Troubleshooting is complete.n


NO - If it is FAILED, then go to 1 and recheck. If it is EXECUTING, keep the driving condition continually until a result comes on. If it is Out of CONDITION, go to 18 and recheck.