P0306

DTC P0301: No.1 Cylinder Misfire Detected (2006 model)

DTC P0302: No.2 Cylinder Misfire Detected (2006 model)

DTC P0303: No.3 Cylinder Misfire Detected (2006 model)

DTC P0304: No.4 Cylinder Misfire Detected (2006 model)

DTC P0305: No.5 Cylinder Misfire Detected (2006 model)

DTC P0306: No.6 Cylinder Misfire Detected (2006 model)

NOTE: Before you troubleshoot, record all freeze data and any on-board snapshot, and review the general troubleshooting information.

1. Clear the DTC with the HDS.
2. Start the engine (in Park or neutral), then let it idle without load.
3. Monitor the OBD STATUS for DTC P0301, P0302, P0303, P0304, P0305, or P0308 in the DTCs MENU with the HDS.

Does the screen indicate FAILED?

YES - Go to step 8.

NO - If the screen indicates PASSED, go to step 4. If the screen indicates EXECUTING, keep driving until a result comes on. If the screen indicates OUT OF CONDITION, wait for several minutes, and recheck.

4. Check the CYL1 MISFIRE, CYL2 MISFIRE, CYL3 MISFIRE, CYL4 MISFIRE, CYL5 MISFIRE, and/or CYL6 MISFIRE in the DATA LIST for 10 minutes with the HDS.

Does CYL1 MISFIRE, CYL2 MISFIRE, CYL3 MISFIRE, CYL4 MISFIRE, CYL5 MISFIRE, and/or CYL6 MISFIRE show misfire counts?

YES - Go to step 8.

NO - Go to step 5.

5. Test-drive the vehicle for several minutes in the range of these recorded freeze data parameters:
- Engine speed
- Engine coolant temperature
- Vehicle speed
- Throttle position
- CLV (calculated load value)

6. Monitor the OBD STATUS for DTC P0301, P0302, P0303, P0304, P0305, or P0306 in the DTCs MENU with the HDS.

Does the screen indicate FAILED?

YES - Go to step 8.

NO - If the screen indicates PASSED, go to step 7. If the screen indicates EXECUTING, keep driving until a result comes on. If the screen indicates OUT OF CONDITION, go to step 6 and recheck.

7. Check the CYL1 MISFIRE, CYL2 MISFIRE, CYL3 MISFIRE, CYL4 MISFIRE, CYL5 MISFIRE, and/or CYL6 MISFIRE in the DATA LIST for 10 minutes with the HDS.

Does CYL1 MISFIRE, CYL2 MISFIRE, CYL3 MISFIRE, CYL4 MISFIRE, CYL5 MISFIRE, and/or CYL6 MISFIRE show misfire counts?

YES - Go to step 8.

NO - Intermittent failure, system is OK at this time. Check the fuel and ignition system circuit connectors for loose wires or poor connections.

8. Turn the ignition switch OFF.
9. Exchange the ignition coil from the problem cylinder with one from another cylinder.
10. Test-drive the vehicle for several minutes in the range of these recorded freeze data parameters:
- Engine speed
- Engine coolant temperature
- Vehicle speed
- Throttle position
- CLV (calculated load value)

11. Check the CYL1 MISFIRE, CYL2 MISFIRE, CYL3 MISFIRE, CYL4 MISFIRE, CYL5 MISFIRE, and/or CYL6 MISFIRE in the DATA LIST for 10 minutes with the HDS.

Does CYL1 MISFIRE, CYL2 MISFIRE, CYL3 MISFIRE, CYL4 MISFIRE, CYL5 MISFIRE, and/or CYL6 MISFIRE show misfire counts?

YES - Go to step 12.

NO - Intermittent misfire due to poor contact at the ignition coil connector (no misfire at this time). Make sure the coil connections are secure.

12. Determine which cylinder had the misfire.

Does the misfire occur in the cylinder where the ignition coil was moved?

YES - Replace the faulty ignition coil, then go to step 54.

NO - Go to step 13.

13. Turn the ignition switch OFF.
14. Exchange the spark plug from the problem cylinder with one from another cylinder.
15. Test-drive the vehicle for several minutes in the range of these recorded freeze data parameters:
- Engine speed
- Engine coolant temperature
- Vehicle speed
- Throttle position
- CLV (calculated load value)

16. Check the CYL1 MISFIRE, CYL2 MISFIRE, CYL3 MISFIRE, CYL4 MISFIRE, CYL5 MISFIRE, and/or CYL6 MISFIRE in the DATA LIST for 10 minutes with the HDS.

Does CYL1 MISFIRE, CYL2 MISFIRE, CYL3 MISFIRE, CYL4 MISFIRE, CYL5 MISFIRE, and/or CYL6 MISFIRE show misfire counts?

YES - Go to step 17.

NO - Intermittent misfire due to spark plug fouling (no misfire at this time).

17. Determine which cylinder had the misfire.

Does the misfire occur in the cylinder where the spark plug was moved?

YES - Replace the faulty spark plug, then go to step 54.

NO - Go to step 18.

18. Turn the ignition switch OFF.
19. Exchange the injector from the problem cylinder with one from the another cylinder.
20. Start the engine, and let it idle 2 minutes.
21. Test-drive the vehicle for several minutes in the range of these recorded freeze data parameters:
- Engine speed
- Engine coolant temperature
- Vehicle speed
- Throttle position
- CLV (calculated load value)

22. Check the CYL1 MISFIRE, CYL2 MISFIRE, CYL3 M1SFIRE, CYL4 MISFIRE, CYL5 MISFIRE, and/or CYL6 MISFIRE in the DATA LIST for 10 minutes with the HDS.

Does CYL1 MISFIRE, CYL2 MISFIRE, CYL3 MISFIRE, CYL4 MISFIRE, CYL5 MISFIRE, and/or CYL6 MISFIRE show misfire counts?

YES - Go to step 23.

NO - Intermittent misfire due to bad contact in the injector connector (no misfire at this time). Check for poor connections or loose terminals at the injector.

23. Determine which cylinder had the misfire.

Does the misfire occur in the cylinder where the injector was exchanged?

YES - Replace the faulty injector, then go to step 54.

NO - Go to step 24.

24. Turn the ignition switch OFF.
25. Disconnect ignition coil 3P connector from the problem cylinder.
26. Turn the ignition switch ON (II).




27. Measure voltage between ignition coil 3P connector terminal No.3 and body ground.

Is there battery voltage?

YES - Go to step 28.

NO - Repair open in the wire between the ignition coil and the ignition coil relay, then go to step 54.

28. Turn the ignition switch OFF.




29. Check for continuity between ignition coil 3P connector terminal No.2 and body ground.

Is there continuity?

YES - Go to step 30.

NO - Repair open in the wire between the ignition coil and G1O1, then go to step 54.

30. Turn the ignition switch OFF.
31. Jump the SCS line with the HDS.
32. Disconnect ECM/PCM Connector A (31P).




33. Check for continuity between body ground and the appropriate ECM/PCM connector terminal (see table).

Is there continuity?

YES - Repair short in the wire between the ECM/PCM and the ignition coil, then go to step 54.

NO - Go to step 34.




34. Connect appropriate ignition coil 3P connector terminal No.1 to body ground with a jumper wire (see table).




35. Check for continuity between body ground and the appropriate ECM/PCM connector terminal (see table).

Is there continuity?

YES - Go to step 36.

NO - Repair open in the wire between the ECM/PCM and the ignition coil, then go to step 54.

36. Reconnect the ignition coil 3P connector and ECM/PCM connector A (31P).
37. Do an engine compression and a cylinder leakdown test.

Did the engine pass both tests?

YES - Go to step 38.

NO - Repair the engine, then go to step 54.

38. Do the VTEC rocker arm test.

Did the engine pass the test?

YES - Go to step 39.

NO - Repair the VTEC rocker arm, then go to step 54.

39. Turn the ignition switch OFF.
40. Jump the SCS line with the HDS.
41. Disconnect ECM/PCM connector A (31P).
42. Turn the ignition switch ON (II).




43. Measure voltage between body ground and the appropriate ECM/PCM connector terminal (see table).

Is there battery voltage?

YES - Go to step 53.

NO - Go to step 44.

44. Turn the ignition switch OFF.
45. Remove the intake manifold.
46. Disconnect the injector 2P connector from the problem cylinder.
47. Turn the ignition switch ON (II).




48. Measure voltage between injector 2P connector terminal No.1 and body ground.

Is there battery voltage?

YES - Go to step 49.

NO - Repair open in the wire between the injector and PGM-FI main relay 1 (FI MAIN), then go to step 54.

49. Turn the ignition switch OFF.




50. Check for continuity between body ground and the appropriate ECM/PCM connector terminal (see table).

Is there continuity?

YES - Repair short in the wire between the ECM/PCM and the injector, then go to step 54.

NO - Go to step 51.




51. Connect appropriate injector 2P connector terminal No.2 to body ground with a jumper wire (see table).




52. Check for continuity between body ground and the appropriate ECM/PCM connector terminal (see table).

Is there continuity?

YES - Go to step 53.

NO - Repair open in the wire between the ECM/PCM and the injector, then go to step 54.




53. Measure resistance between injector 2P connector terminals No.1 and No.2.

Is there 10 - 13 Ohms?

YES - Go to step 63.

NO - Replace the injector, then go to step 54.

54. Reconnect all connectors.
55. Turn the ignition switch ON (II).
56. Reset the ECM/PCM with the HDS.
57. Clear the CKP pattern with the HDS.
58. Do the ECM/PCM idle learn procedure.
59. Do the CKP pattern learn procedure.
60. Test-drive the vehicle for several minutes in the range of these recorded freeze data parameters:
- Engine speed
- Engine coolant temperature
- Vehicle speed
- Throttle position
- CLV (calculated load value)

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

Are any Temporary DTCs or DTCs indicated?

YES - If DTC P0301, P0302, P0303, P0304, P0305, or P0306 are indicated, check for poor connections or loose terminals at the ignition coil, the injector, and the ECM/PCM, then go to troubleshooting DTC P0301, P0302, P0303, P0304, P0305, or P0306. It any other Temporary DTCs or DTCs are indicated, go to the indicated DTC's troubleshooting.

NO - Go to step 62.

62. Monitor the OBD STATUS for DTC P0301, P0302, P0303, P0304, P0305, or P0306 in the DTCs MENU with the HDS.

Does the screen indicate PASSED?

YES -Troubleshooting is complete.

NO - If the screen indicates FAILED, go to step 1 and recheck. If the screen indicates EXECUTING, keep driving until a result comes on. If the screen indicates OUT OF CONDITION, go to step 60 and recheck.

63. Update the ECM/PCM if it does not have the latest software, or substitute a known-good ECM/PCM.
64. Test-drive the vehicle for several minutes in the range of these recorded freeze data parameters:
- Engine speed
- Engine coolant temperature
- Vehicle speed
- Throttle position
- CLV (calculated load value)

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

Are any Temporary DTCs or DTCs indicated?

YES - If DTC P0301, P0302, P0303, P0304, P0305, or P0306 are indicated, check for poor connections or loose terminals at the injector, the ignition coil, and the ECM/PCM, then go to step 1. If any other Temporary DTCs or DTCs are indicated, go to the indicated DTC's troubleshooting.

NO - If the ECM/PCM was updated, troubleshooting is complete. If the ECM/PCM was substituted, replace the original ECM/PCM.