Code No. P0301: No. 1 Cylinder Misfire Detected




OPERATION




FUNCTION




TROUBLE JUDGEMENT


Check Conditions
Judgement Criterion (change in the angular acceleration of the crankshaft is used for misfire detection).
or


FAIL-SAFE AND BACKUP FUNCTION




PROBABLE CAUSES




DIAGNOSIS PROCEDURE


STEP 1. Visual check of ignition spark on No. 1 cylinder.



  • Remove the spark plug and install it to the ignition coil.
  • Connect the ignition coil connector.
  • Disconnect all injector connectors.
  • At the engine start, check spark plug produces a spark.

Q. Is the check result normal?

Go to Step 2
Check Inspection Procedure - ignition circuit system (Refer to ).

STEP 2. Check No. 1 injector itself.



  • No. 1 injector connector check.
  • Injector check (Refer to ).

Q. Is the check result normal?

Go to Step 3
Repair or replace the connector, or replace the No. 1 injector.

STEP 3. Check harness between engine control relay connector terminal and No. 1 injector connector terminal.



  • Check power supply line for damage.

Q. Is the check result normal?

Go to Step 4
Repair or replace the connector, or repair the damaged harness wire.

STEP 4. Check harness between No. 1 injector connector terminal and engine-ECU connector terminal INJ1.



  • Check output line for damage.

Q. Is the check result normal?

Go to Step 5
Repair or replace the connector, or repair the damaged harness wire.

STEP 5. Check compression pressure of No. 1 cylinder.



  • Check the compression pressure (Refer to GROUP 11C - On-vehicle Service - Compression Pressure Check .

Q. Is the check result normal?

Go to Step 6
Repair.

STEP 6. M.U.T.-III diagnosis code



  • Reconfirmation of diagnosis code.

Q. Is the diagnosis code stored?

Replace the engine-ECU.
Intermittent malfunction (Refer to GROUP 00 - How to Use Troubleshooting/Inspection Service Points - How to Cope with Intermittent Malfunctions ).