J35A7
DTC Troubleshooting: P0301, P0302, P0303, P0304, P0305, P0306
DTC P0301:
No. 1 Cylinder Misfire Detected
(J35A7 engine ('08-10 models))
DTC P0302:
No. 2 Cylinder Misfire Detected
(J35A7 engine ('08-10 models))
DTC P0303:
No. 3 Cylinder Misfire Detected
(J35A7 engine ('08-10 models))
DTC P0304:
No. 4 Cylinder Misfire Detected
(J35A7 engine ('08-10 models))
DTC P0305:
No. 5 Cylinder Misfire Detected
(J35A7 engine ('08-10 models))
DTC P0306:
No. 6 Cylinder Misfire Detected
(J35A7 engine ('08-10 models))
NOTE: Before you troubleshoot, record all freeze data and any on-board snapshot, and review the general troubleshooting information Initial Inspection and Diagnostic Overview.
1. Turn the ignition switch to ON (II).
2. Clear the DTC with the HDS.
3. Start the engine, and let it idle without load for 2 minutes (in P or N).
4. 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 9.
NO -
If the screen indicates PASSED, go to step 5. If the screen indicates EXECUTING, keep idling until a result comes on. If the screen indicates OUT OF CONDITION or NOT COMPLETED, wait for several minutes, and recheck.
5. 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 9.
NO -
Go to step 6.
6. Test-drive the vehicle for several minutes in the range of these recorded freeze data parameters:
- ENGINE SPEED
- VSS
- REL TP SENSOR
- CLV (calculated load value)
- GEAR POSITION
- ECT SENSOR 1
7. 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 9.
NO -
If the screen indicates PASSED, go to step 8. If the screen indicates EXECUTING, keep driving until a result comes on. If the screen indicates OUT OF CONDITION or NOT COMPLETED, go to step 6.
8. 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 9.
NO -
Intermittent failure, the system is OK at this time. Check for poor connections or loose terminals in the fuel system and the ignition system.�
9. Turn the ignition switch to LOCK (0).
10. Exchange the ignition coil from the problem cylinder with one from another cylinder.
11. Reconnect all connectors.
12. Test-drive the vehicle for several minutes in the range of these recorded freeze data parameters:
- ENGINE SPEED
- VSS
- REL TP SENSOR
- CLV (calculated load value)
- GEAR POSITION
- ECT SENSOR 1
13. 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 14.
NO -
Intermittent failure due to poor contact at the ignition coil contactor(s) (no misfire at this time). Make sure that the ignition coil connectors are secure.�
14. 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 Ignition Coil and Spark Plug Removal/Installation (J35A7), then go to step 46.
NO -
Go to step 15.
15. Turn the ignition switch to LOCK (0).
16. Exchange the spark plug from the problem cylinder with from another cylinder.
17. Reconnect all connectors.
18. Test-drive the vehicle for several minutes in the range of these recorded freeze data parameters:
- ENGINE SPEED
- VSS
- REL TP SENSOR
- CLV (calculated load value)
- GEAR POSITION
- ECT SENSOR 1
19. 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 20.
NO -
Intermittent failure due to spark plug fouling (no misfire at this time).�
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 46.
NO -
Go to step 21.
21. Turn the ignition switch to LOCK (0).
22. Jump the SCS line with the HDS.
23. Disconnect PCM connector B (49P).
24. Remove the intake manifold Intake Manifold Removal/Installation.
25. Turn the ignition switch to ON (II).
26. Measure the voltage between body ground and the appropriate PCM connector terminal (see table).
Is there battery voltage?
YES -
Go to step 33.
NO -
Go to step 27.
27. Turn the ignition switch to LOCK (0).
28. Disconnect the injector 2P connector from the problem cylinder.
29. Turn the ignition switch to ON (II).
30. Measure the voltage between injector 2P connector terminal No. 1 and body ground.
Is there battery voltage?
YES -
Go to step 31.
NO -
Repair open in the wire between the injector and PGM-FI main relay 1 (FI MAIN), then go to step 46.
31. Turn the ignition switch to LOCK (0).
32. Check for continuity between body ground and the appropriate PCM connector terminal (see table).
Is there continuity?
YES -
Repair short in the wire between the PCM and the injector, then go to step 46.
NO -
Go to step 33.
33. Check for continuity between appropriate injector 2P connector terminal No. 2 and the appropriate PCM connector terminal of the problem cylinder (see table).
Is there continuity?
YES -
Check for poor connections or loose terminals at the injector and PGM-FI main relay 1 (FI MAIN), then go to step 34.
NO -
Repair open in the wire between the PCM and the injector, then go to step 46.
34. At the injector side, measure the resistance between injector 2P connector terminals No. 1 and No. 2.
Is there 10-13 Ohms?
YES -
Go to step 35.
NO -
Replace the injector Service and Repair, then go to step 46.
35. Exchange the injector from the problem cylinder with one from another cylinder. Also check the injector fuel inlet screen for debris, and clean if needed.
36. Reconnect all connectors, and install the intake manifold Intake Manifold Removal/Installation.
37. Turn the ignition switch to ON (II).
38. Clear the DTCs with the HDS.
39. Start the engine, and let it idle without load (in P or N) for 2 minutes.
40. Test-drive the vehicle for several minutes in the range of these recorded freeze data parameters:
- ENGINE SPEED
- VSS
- REL TP SENSOR
- CLV (calculated load value)
- GEAR POSITION
- ECT SENSOR 1
41. 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 42.
NO -
Intermittent failure due to poor contact in the injector connector(s) (no misfire at this time). Check for poor connections or loose terminals at the injector(s).�
42. Determine which cylinder had the misfire.
Does the misfire occur in the cylinder where the injector was moved?
YES -
Replace the faulty injector Service and Repair, then go to step 46.
NO -
Go to step 43.
43. Turn the ignition switch to LOCK (0).
44. Do an engine compression and a cylinder leakdown test Engine Compression Inspection (J35A7).
Did the engine pass both tests?
YES -
Go to step 45.
NO -
Repair the engine, then go to step 46.
45. Do the variable cylinder rocker arm test Variable Cylinder Management Rocker Arm Test (J35A7).
Did the engine pass the test?
YES -
Go to step 53.
NO -
Repair the rocker arm, then go to step 46.
46. Reconnect all connectors.
47. Reset the PCM with the HDS.
48. Do the PCM idle learn procedure PCM Idle Learn Procedure.
49. Do the CKP pattern clear/CKP pattern learn procedure Initial Inspection and Diagnostic Overview.
50. Test-drive the vehicle for several minutes in the range of these recorded freeze data parameters:
- ENGINE SPEED
- VSS
- REL TP SENSOR
- CLV (calculated load value)
- GEAR POSITION
- ECT SENSOR 1
51. Check for Pending or Confirmed DTCs with the HDS.
Is DTC P0301, P0302, P0303, P0304, P0305, or P0306 indicated?
YES -
Check for poor connections or loose terminals at the ignition coil(s), the injector(s), and the PCM, then go to troubleshooting DTC P0300, P0301, P0302, P0303, P0304, P0305, or P0306 P0300.
NO -
Go to step 52.
52. 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. If any other Pending or Confirmed DTCs were indicated in step 51, go to the indicated DTC's troubleshooting.�
NO -
If the screen indicates FAILED, check for poor connections or loose terminals at the ignition coil(s), the injector(s), and the PCM, then go to step 1. If the screen indicates EXECUTING, keep driving until a result comes on. If the screen indicates OUT OF CONDITION or NOT COMPLETED, go to step 50.
53. Reconnect all connectors.
54. Update the PCM if it does not have the latest software PCM Update, or substitute a known-good PCM Initial Inspection and Diagnostic Overview.
55. Test-drive the vehicle for several minutes in the range of these recorded freeze data parameters:
- ENGINE SPEED
- VSS
- REL TP SENSOR
- CLV (calculated load value)
- GEAR POSITION
- ECT SENSOR 1
56. Check for Pending or Confirmed DTCs with the HDS.
Is DTC P0301, P0302, P0303, P0304, P0305, or P0306 indicated?
YES -
Check for poor connections or loose terminals at the ignition coil(s), the injector(s), and the PCM. If the PCM was updated, substitute a known-good PCM Initial Inspection and Diagnostic Overview, then go to step 55. If the PCM was substituted, go to step 1.
NO -
Go to step 57.
57. 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 -
If the PCM was updated, troubleshooting is complete. If the PCM was substituted, replace the original PCM Service and Repair. If any other Pending or Confirmed DTCs were indicated in step 56, go to the indicated DTC's troubleshooting.�
NO -
If the screen indicates FAILED, check for poor connections or loose terminals at the ignition coil(s), the injector(s), and the PCM. If the PCM was updated, substitute a known-good PCM Initial Inspection and Diagnostic Overview, then go to step 55. If the PCM was substituted, go to step 1. If the screen indicates EXECUTING, keep driving until a result comes on. If the screen indicates OUT OF CONDITION or NOT COMPLETED, go to step 55.