Code No. P0301: No. 1 Cylinder Misfire Detected








OPERATION



  • Refer to Code No. P0201: No. 1 Injector System .

FUNCTION



  • If a misfire occurs while the engine is running, the engine speed changes for an instant.
  • The engine-A/T-ECU checks for such changes in engine speed.

TROUBLE JUDGMENT


Check Conditions
  • Engine speed is 440 - 4,500 r/min.
  • Engine coolant temperature and intake air temperature are more than -10°C.
  • Barometric pressure is less than 106 kPa.
  • Volumetric efficiency is between 15 % and 100 %.
  • The learning compensation control that absorbs the difference in the target location showing the crank position is completed.
  • During the usual operation, the amount of throttle change is small: between -0.06 V/10 ms and +0.06 V/10 ms.
Judgment Criteria (change in the angular acceleration of the crankshaft is used for misfire detection).
  • Misfire has occurred more frequently than the limit during the last 200 revolutions (when the catalyst temperature has been 950°C or higher).
    or
  • When the engine often misfires within the last 1,000 revolutions from when the exhaust gas exceeds the E-OBD regulation value.

PROBABLE CAUSES



  • Ignition system related part(s) failed
  • Low compression pressure
  • Failed engine-A/T-ECU

DIAGNOSIS PROCEDURE

STEP 1. Check ignition coil spark.


Q. Is the check result normal?
Go to Step 2 .
Check ignition circuit system (Refer to Inspection procedure 25 )

STEP 2. Connector check: B-119 No. 1 injector connector

Q. Is the check result normal?
Go to Step 3 .
Repair or replace the connector.

STEP 3. Check No. 1 injector itself.

  • Check Injector itself (Refer to ).

Q. Is the check result normal?
Go to Step 4 .
Replace the No. 1 injector.

STEP 4. Connector check: B-15X engine control relay connector and B-212 engine-A/T-ECU connector

Q. Are the check results normal?
Go to Step 5 .
Repair or replace the connector.

STEP 5. Check harness between B-15X (terminal No. 1) engine control relay connector and B-119 (terminal No. 1) No. 1 injector connector.


note Before checking harness, check intermediate connector B-28, and repair if necessary.

  • Check power supply line for damage.

Q. Is the check result normal?
Go to Step 6 .
Repair the damaged harness wire.

STEP 6. Check harness between B-119 (terminal No. 2) No. 1 injector connector and D-212 (terminal No. 1) engine-A/T-ECU connector
note Before checking harness, check intermediate connector B-28, and repair if necessary.

  • Check output line for damage.

Q. Is the check result normal?
Go to Step 7 .
Repair the damaged harness wire.

STEP 7. Fuel pressure measurement.

  • Fuel pressure measurement (Refer to ).

Q. Is the check result normal?
Go to Step 8
Repair.

STEP 8. M.U.T.-III diagnosis code

  • Reconfirmation of diagnosis code.

Q. Is the diagnosis code set?
Replace the engine-A/T-ECU.
Intermittent malfunction (Refer to GROUP 00 - How to Use Troubleshooting/Inspection Service Points - How to Cope with Intermittent Malfunctions ).