PGM-FI System

DTC Troubleshooting (cont'd)

11-380  

DTC P0301: No. 1 Cylinder Misfire

DTC P0302: No. 2 Cylinder Misfire

DTC P0303: No. 3 Cylinder Misfire

DTC P0304: No. 4 Cylinder Misfire

  1. After checking and recording the freeze data, reset the ECM/PCM (see page 11-312). 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 step 3.

NO

- Go to step 30.


  1. Turn the ignition switch OFF, and reset the ECM/PCM.
  2. Exchange the ignition coil from the problem cylinder with one from another cylinder.
  3. Test-drive the vehicle several times in the range of the freeze data or under various conditions if there was no freeze data.
  4. 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 step 7.

NO

- Intermittent misfire due to poor contact at the ignition coil connector (no misfire at this time).


  1. 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.

NO

- Go to step 8.

  1. Turn the ignition switch OFF, and reset the ECM/PCM.
  2. Exchange the spark plug from the problem cylinder with one from another cylinder.
  3. Test-drive the vehicle several times in the range of the freeze data or under various conditions if there was no freeze data.
  4. 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 step 12.

NO

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


  1. 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.

NO

- Go to step 13.


  1. Turn the ignition switch OFF, and reset the ECM/PCM.
  2. Exchange the injector in the problem cylinder with one from another cylinder.
  3. Let the engine idle for 2 minutes.