P0302

DTC P0301: No. 1 Cylinder Misfire Detected

DTC P0302: No. 2 Cylinder Misfire Detected

DTC P0303: No. 3 Cylinder Misfire Detected

DTC P0304: No. 4 Cylinder Misfire Detected

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), and let it idle without load.
3. Monitor the OBD STATUS for DTC P0301, P0302, P0303, or P0304 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, 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 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
- VSS
- TP SENSOR
- CLV (calculated load value)
- ECT SENSOR

6. Monitor the OBD STATUS for DTC P0301, P0302, P0303, or P0304 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 5 and recheck.

7. 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 step 8.

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

8. Turn the ignition switch OFF.
9. Remove the intake manifold cover.
10. Start the engine, and listen for a clicking sound at the injector of the problem cylinder.

Does the injector click?

YES - Go to step 11.

NO - Go to step 42.

11. Turn the ignition switch OFF.
12. Exchange the ignition coil from the problem cylinder with one from another cylinder.
13. Test-drive the vehicle for several minutes in the range of these recorded freeze data parameters:
- ENGINE SPEED
- VSS
- TP SENSOR
- CLV (calculated load value)
- ECT SENSOR

14. 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 step 15.

NO - Intermittent misfire due to poor contact at the ignition coil connector (no misfire at this time). Check for poor connections or loose terminals at the ignition coil. Then clear the CKP pattern with the HDS, and do the CKP pattern learn procedure.

15. 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 61.

NO - Go to step 16.

16. Turn the ignition switch OFF.
17. Exchange the spark plug from the problem cylinder with one from another cylinder.
18. Test-drive the vehicle for several minutes in the range of these recorded freeze data parameters:
- ENGINE SPEED
- VSS
- TP SENSOR
- CLV (calculated load value)
- ECT SENSOR

19. 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 step 20.

NO - Intermittent misfire due to spark plug fouling (no misfire at this time). Clear the CKP pattern with the HDS, then do the CKP pattern learn procedure.

20. 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 63.

NO - Go to step 21.

21. Turn the ignition switch OFF.
22. Exchange the injector from the problem cylinder with one from another cylinder.
23. Start the engine, and let it idle 2 minutes.
24. Test-drive the vehicle for several minutes in the range of these recorded freeze data parameters:
- ENGINE SPEED
- VSS
- TP SENSOR
- CLV (calculated load value)
- ECT SENSOR

25. 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 step 26.

NO - Intermittent misfire due to bad contact in the injector connector (no misfire at this time). Check for poor connections or loose terminals s at the injector. Clear the CKP pattern with the HDS, then do the CKP pattern learn procedure.

26. 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 61.

NO - Go to step 27.

27. Turn the ignition switch OFF.
28. Disconnect the ignition coil 3P connector from the problem cylinder.
29. Turn the ignition switch ON (II).




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

Is there battery voltage?

YES - Go to step 31.

NO - Repair open in the wire between the ignition coil and the No. 1 ignition coil (15 A) fuse, then go to step 61.

31. Turn the ignition switch OFF.




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

Is there continuity?

YES - go to step 33.

NO - Repair open in the wire between the ignition coil and G102, then go to step 62.

33. Turn the ignition switch OFF.
34. Jump the SCS line with the HDS.
35. Disconnect ECM/PCM connector A (31P).




36. 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 61.

NO - Go to step 37.




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




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

Is there continuity?

YES - Go to step 39.

NO - Repair open in the wire between the ECM/PCM and the ignition coil, then go to step 61.

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

Did the engine pass both tests?

YES - Go to step 41.

NO - Repair the engine, then go to step 61.

41. Do the VTEC rocker arms test.

Did the VTEC rocker arms pass the test?

YES - Go to step 69.

NO - Repair the VTEC rocker arm, then go to step 61.

42. Turn the ignition switch OFF.
43. Jump the SCS line with the HDS.
44. Disconnect ECM/PCM connector B (24P).
45. Turn the ignition switch ON (II).




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

Is there battery voltage?

YES - Go to step 55.

NO - Go to step 47.

47. Turn the ignition switch OFF.
48. Disconnect the injector 2P connector from the problem cylinder.
49. Turn the ignition switch ON (II).




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

Is there battery voltage?

YES - Go to step 51.

NO - Repair open in the wire between the injector and PGM-FI main relay 1 (FI MAIN), then go to step 61.

51. Turn the ignition switch OFF.




52. 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 61.

NO - Go to step 53.




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




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

Is there continuity?

YES - Go to step 55.

NO - Repair open in the wire between the ECM/PCM and the injector, then go to step 61.




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

Is there 10-13 Ohms?

YES - Go to step 56.

NO - Replace the injector, then go to step 61.

56. Exchange a known-good injector from another cylinder with the one from the problem cylinder.
57. Reconnect ECM/PCM connector B (24P).
58. Start the engine, and let it idle 2 minutes.
59. Test-drive the vehicle for several minutes in the range of these recorded freeze data parameters:
- ENGINE SPEED
- VSS
- TP SENSOR
- CLV (calculated load value)
- ECT SENSOR

60. 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 step 70.

NO - Replace the original injector, then go to step 61.

61. Reconnect all connectors.
62. Turn the ignition switch ON (II).
63. Reset the ECM/PCM with the HDS.
64. Clear the CKP pattern with the HDS.
65. Do the ECM/PCM idle learn procedure.
66. Do the CKP pattern learn procedure.
67. Test-drive the vehicle for several minutes in these range of the recorded freeze data parameters:
- ENGINE SPEED
- VSS
- TP SENSOR
- CLV (calculated load value)
- ECT SENSOR

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

Are any Temporary DTCs or DTCs indicated?

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

NO - Go to step 69.

69. Monitor the OBD STATUS for DTC P0301, P0302, P0303, or P0304 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 67 and recheck.

70. Update the ECM/PCM if it does not have the latest software, or substitute a known-good ECM/PCM.
71. Test-drive the vehicle for several minutes in the range of these recorded freeze data parameters:
- ENGINE SPEED
- VSS
- TP SENSOR
- CLV (calculated load value)
- ECT SENSOR

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

Are any Temporary DTCs or DTCs indicated?

YES - If DTC P0301, P0302, P0303, or P0304 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.