| DTC P0301 (71-1): | No. 1 Cylinder Misfire |
| DTC P0303 (73-1): | No. 3 Cylinder Misfire |
| 1. | After checking and recording the freeze data, reset the ECM/PCM. If there is no freeze data of the misfire, just clear the DTC. |
| 2. | Start the engine, and listen for a clicking sound at the injector at the problem cylinder. Does it click? YES - Go to 3. NO - Go to 24. |
| 3. | Turn the ignition switch OFF, and reset the ECM/PCM. |
| 4. | Exchange the ignition coil from the problem cylinder with one from another cylinder. |
| 5. | Test-drive the vehicle several times in the range of the freeze data or under various conditions if there was no freeze data. |
| 6. | Check the DTC or the Temporary DTC with the scan tool. Is DTC or Temporary DTC P0301, P0302, P0303 or P0304 indicated? YES - Go to 7. NO - Intermittent misfire due to poor contact at the ignition coil connector (no misfire at this time).n |
| 7. | Determine which cylinder(s) had the misfire. Does the misfire occur in the other cylinder whose ignition coil was exchanged? YES - Replace the faulty ignition coil.n NO - Go to 8. |
| 8. | Turn the ignition switch OFF, and reset the ECM/PCM. |
| 9. | Exchange the spark plug from the problem cylinder with one from another cylinder. |
| 10. | Test-drive the vehicle several times in the range of the freeze data or under various conditions if there was no freeze data. |
| 11. | Check the DTC or the Temporary DTC with the scan Tool. Is DTC or Temporary DTC P0301, P0302, P0303 or P0304 indicated? YES - Go to 12. NO - Intermittent misfire due to spark plug fouling, etc. (no misfire at this time).n |
| 12. | Determine which cylinder(s) had the misfire. Does the misfire occur in the other cylinder whose spark plug was exchanged? YES - Replace the faulty spark plug.n NO - Go to 13. |
| 13. | Turn the ignition switch OFF, and reset the ECM/PCM. |
| 14. | Exchange the injector from the problem cylinder with one from the another cylinder. |
| 15. | Let the engine idle for 2 minutes. |
| 16. | Test-drive the vehicle several times in the range of the freeze data or under various conditions if there was no freeze data. |
| 17. | Check the DTC or the Temporary DTC with the scan Tool. Is DTC or Temporary DTC P0301, P0302, P0303 or P0304 indicated? YES - Go to 18. NO - Intermittent misfire due to bad contact at the injector connector (no misfire at this time).n |
| 18. | Determine which cylinder(s) had the misfire. Does the misfire occur in the other cylinder whose injector was exchanged? YES - Replace the faulty injector.n NO - Go to 19. |
| 19. | Turn the ignition switch OFF. |
| 20. | Disconnect the ignition coil 3P connector from the problem cylinder. |
| 21. | Turn the ignition switch ON (II). |
| 22. | Measure voltage between the ignition coil 3P connector terminal No. 3 and body ground.
Is there battery voltage? YES - Go to 23. NO - Repair open or short in the wire between the No. 7 (15A), (No. 9 (15A))* fuse and the ignition coil. *: rear ignition coil n |
| 23. | Check the compression. Is the engine compression? YES - Substitute a known-good ECM/PCM and recheck. If symptom/indication goes away, replace the original ECM/ PCM.n NO - Repair the engine.n |
| 24. | Turn the ignition switch OFF. |
| 25. | Disconnect the negative cable from the battery. |
| 26. | Disconnect ECM/PCM connector B (24P). |
| 27. | Reconnect the negative cable to the battery. |
| 28. | Turn the ignition switch ON (II). |
| 29. | Measure voltage between body ground and the appropriate ECM/PCM connector terminal (see table).
Is there battery voltage? YES - Go to 30. NO - Go to 38. |
| 30. | Turn the ignition switch OFF, and remove the engine cover. |
| 31. | Disconnect the injector 2P connector on the problem cylinder. |
| 32. | Measure the resistance between the injector 2P connector terminals No. 1 and No. 2.
Is there 10 W-13W? YES - Go to 33. NO - Replace the injector.n |
| 33. | Exchange the injector from the problem cylinder with one from another cylinder. |
| 34. | Let the engine idle for 2 minutes. |
| 35. | Test-drive the vehicle several times in the range of the freeze data or under various conditions if there was no freeze data. |
| 36. | Check the DTC or the Temporary DTC with a scan tool. Is DTC or Temporary DTC P0301, P0302, P0303, or P0304 indicated? YES - Go to 37. NO - Intermittent misfire due to injector malfunction etc.n |
| 37. | Determine which cylinder(s) had the misfire. Does the misfire occur in the other cylinder whose injector was exchanged? YES - Replace the faulty injector.n NO - Substitute a known-good ECM/PCM and recheck. If symptom/indication goes away, replace the original ECM/ PCM.n |
| 38. | Turn the ignition switch OFF and remove the engine cover. |
| 39. | Disconnect the injector 2P connector on the problem cylinder. |
| 40. | Turn the ignition switch ON (II). |
| 41. | Measure voltage between the injector 2P connector terminal No. 1 and body ground.
Is there battery voltage? YES - Go to 42. NO - Repair open in the wire between the injector and the PGM-FI main relay.n |
| 42. | Turn the ignition switch OFF. |
| 43. | 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.n NO - Go to 44. |
| 44. | Connect the appropriate injector 2P connector terminal No. 2 to body ground with a jumper wire (see table).
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| 45. | Check for continuity between body ground and the appropriate ECM/PCM connector terminal (see table).
Is there continuity? YES - Replace the injector, then recheck.n NO - Repair open in the wire between the ECM/ PCM and the injector.n |