ECD SYSTEM, Diagnostic DTC:P0301, P0302, P0303, P0304

DTC Code DTC Name
P0301 Cylinder 1 Misfire Detected
P0302 Cylinder 2 Misfire Detected
P0303 Cylinder 3 Misfire Detected
P0304 Cylinder 4 Misfire Detected

DESCRIPTION

Tech Tips

For more information on the injector assemblies and common rail system, refer to System Description Click here.

The ECM detects combustion deterioration for a specific cylinder.

DTC No. DTC Detection Condition Trouble Area
P0301

While the engine speed is approximately 1000 rpm, it is detected that the number of misfires of the No. 1 cylinder is equal to or greater than the standard value.

(3 trip detection logic)


  • No. 1 injector assembly

  • Compression pressure

  • Valve timing

  • EGR Valve

  • Fuel with low cetane number used

  • Flywheel

  • ECM

DTC No. DTC Detection Condition Trouble Area
P0302

While the engine speed is approximately 1000 rpm, it is detected that the number of misfires of the No. 2 cylinder is equal to or greater than the standard value.

(3 trip detection logic)


  • No. 2 injector assembly

  • Compression pressure

  • Valve timing

  • EGR Valve

  • Fuel with low cetane number used

  • Flywheel

  • ECM

DTC No. DTC Detection Condition Trouble Area
P0303

While the engine speed is approximately 1000 rpm, it is detected that the number of misfires of the No. 3 cylinder is equal to or greater than the standard value.

(3 trip detection logic)


  • No. 3 injector assembly

  • Compression pressure

  • Valve timing

  • EGR Valve

  • Fuel with low cetane number used

  • Flywheel

  • ECM

DTC No. DTC Detection Condition Trouble Area
P0304

While the engine speed is approximately 1000 rpm, it is detected that the number of misfires of the No. 4 cylinder is equal to or greater than the standard value.

(3 trip detection logic)


  • No. 4 injector assembly

  • Compression pressure

  • Valve timing

  • EGR Valve

  • Fuel with low cetane number used

  • Flywheel

  • ECM

Related Data List
DTC No. Data List

P0301

P0302

P0303

P0304


  • Cylinder 1 Quantity Compensation

  • Cylinder 2 Quantity Compensation

  • Cylinder 3 Quantity Compensation

  • Cylinder 4 Quantity Compensation

  • Target Common Rail Pressure

  • Common Rail Pressure

Tech Tips


  • If DTC P0301, P0302, P0303 or P0304 is stored, the following symptoms may appear:


    • Rough idle

    • Poor driveability

  • After confirming DTC P0301, P0302, P0303 or P0304, check the internal fuel pressure on the GTS by entering the following menus: Powertrain / Engine and ECT / Data List / Common Rail Pressure, Target Common Rail Pressure.

WIRING DIAGRAM

Refer to DTC P0201 Click here.

CAUTION / NOTICE / HINT

Note


  • After replacing the ECM, the new ECM needs registration and initialization Click here.

  • After replacing an injector assembly, the ECM needs registration Click here.

  • After replacing the EGR valve assembly, the ECM needs initialization Click here.

Tech Tips

Read freeze frame data using the intelligent tester. Freeze frame data records the engine condition when malfunctions are detected. When troubleshooting, freeze frame data can help determine if the vehicle was moving or stationary, if the engine was warmed up or not, and other data from the time the malfunction occurred.

PROCEDURE


  1. CHECK FOR ANY OTHER DTCS OUTPUT (IN ADDITION TO DTC P0301, P0302, P0303 OR P0304)


    1. Connect the GTS to the DLC3.

    2. Turn the ignition switch to ON and turn the GTS on.

    3. Enter the following menus: Powertrain / Engine and ECT / Trouble Codes.

    4. Read the DTCs.

      Result
      Result Proceed to
      P0301, P0302, P0303 or P0304 is output A
      P0301, P0302, P0303 or P0304 and other DTCs are output B

      Tech Tips

      If any DTCs other than P0301, P0302, P0303 or P0304 are output, troubleshoot those DTCs first.


    B
    A
  2. CHECK HARNESS AND CONNECTOR (ENGINE WIRE HARNESS)


    1. Check the wire harness and connector connections.

      OK
      The wire harness and connectors have been connected securely and there are good connections.
    2. Disconnect the injector assembly connector.

    3. Disconnect the ECM connector.

    4. Measure the resistance according to the value(s) in the table below.

      Standard Resistance
      Tester Connection Condition Specified Condition
      C1-2 (#10) - B91-29 (IJ1+) Always Below 1 Ω
      C1-1 (#1) - B91-59 (IJ1-) Always Below 1 Ω
      C2-2 (#20) - B91-28 (IJ2+) Always Below 1 Ω
      C2-1 (#2) - B91-58 (IJ2-) Always Below 1 Ω
      C3-2 (#30) - B91-27 (IJ3+) Always Below 1 Ω
      C3-1 (#3) - B91-57 (IJ3-) Always Below 1 Ω
      C4-2 (#40) - B91-26 (IJ4+) Always Below 1 Ω
      C4-1 (#4) - B91-56 (IJ4-) Always Below 1 Ω
      C1-2 (#10) or B91-29 (IJ1+) - Body ground Always 10 kΩ or higher
      C1-1 (#1) or B91-59 (IJ1-) - Body ground Always 10 kΩ or higher
      C2-2 (#20) or B91-28 (IJ2+) - Body ground Always 10 kΩ or higher
      C2-1 (#2) or B91-58 (IJ2-) - Body ground Always 10 kΩ or higher
      C3-2 (#30) or B91-27 (IJ3+) - Body ground Always 10 kΩ or higher
      C3-1 (#3) or B91-57 (IJ3-) - Body ground Always 10 kΩ or higher
      C4-2 (#40) or B91-26 (IJ4+) - Body ground Always 10 kΩ or higher
      C4-1 (#4) or B91-56 (IJ4-) - Body ground Always 10 kΩ or higher

    NG
    OK
  3. CHECK INJECTOR ASSEMBLY


    1. Check the installation condition of the injector.

      OK
      Injector is installed correctly.

    NG
    OK
  4. PERFORM ACTIVE TEST USING GTS (ACTUATOR TEST OF EGR-VALVE)


    1. Connect the GTS to the DLC3.

    2. Turn the ignition switch to ON and turn the GTS on.

    3. Start the engine.

    4. Enter the following menus: Powertrain / Engine and ECT / Active Test / Actuator Test of EGR-Valve / Data List / Target EGR Position and Actual EGR Valve Pos.

    5. Perform the following steps 1 to 4.

    6. Step 1


      1. Perform Actuator Test of EGR-Valve with control value of 0% (opening ratio in %).

      2. Monitor the difference of the control value and EGR valve Actuator Position value (0 +/- 3%). EGR valve must operate within 1 second.

    7. Step 2


      1. Wait for 2 seconds or more.

    8. Step 3


      1. Perform Actuator Test of EGR-Valve with control value of 94% (opening ratio in %).

      2. Monitor the difference of the control value and EGR valve Actuator Position value (0 +/- 3%). EGR valve must operate within 1 second.

    9. Step 4


      1. Wait for 2 seconds or more.

    10. Perform the above steps 1 to 4 and check that the part operates as specified.

      OK
      Part operates as specified.
    11. Check the EGR valve for operation malfunctions and whether it is fully closed.

      OK
      EGR valve is moving correctly and fully closed.

    NG
    OK
  5. CHECK CYLINDER COMPRESSION PRESSURE


    1. Check the cylinder compression pressure Click here.


    NG
    OK
  6. CHECK FUEL QUALITY


    1. Check the fuel quality.


    NG
    OK
  7. CHECK ENGINE MOUNTING INSULATOR


    1. Check the engine mounting insulator for deformation.

      OK
      Engine mounting insulator is not deformation.

      Tech Tips

      There are discernible vibrations when the engine is running.


    NG
    OK
  8. CHECK FLYWHEEL ASSEMBLY


    1. Check the flywheel for deformation and deviation.

      OK
      flywheel is not deformation and not deviation.

      Tech Tips


      • There are discernible vibrations when the engine is running.

      • If there are no malfunctions up to this step, DTCs may be stored due to vehicle vibrations. Clear the DTCs once and perform a drive test.


    OK
    NG
  9. REPAIR OR REPLACE HARNESS OR CONNECTOR


    1. Repair or replace the harness or connector.


    NEXT
  10. REPLACE INJECTOR ASSEMBLY


    1. Replace the injector assembly Click here.

    2. Register the injector assembly compensation code Click here.


    NEXT
  11. REPLACE EGR VALVE ASSEMBLY


    1. Replace the EGR valve assembly Click here.

    2. Perform EGR learning value reset Click here.


    NEXT
  12. CHECK ENGINE TO DETERMINE CAUSE OF LOW COMPRESSION


    NEXT
  13. REPLACE FUEL


    1. Replace the fuel.


    NEXT
  14. REPLACE ENGINE MOUNTING INSULATOR


    1. Replace the engine mounting insulator.


    NEXT
  15. REPLACE FLYWHEEL ASSEMBLY


    1. Replace the flywheel assembly.


    NEXT
  16. CONFIRM WHETHER MALFUNCTION HAS BEEN SUCCESSFULLY REPAIRED


    1. Connect the GTS to the DLC3.

    2. Turn the ignition switch to ON and turn the GTS on.

    3. Clear the DTCs Click here.

    4. Turn the ignition switch off and wait for 60 seconds or more [A].

    5. Perform road test [B].

    6. Repeat [A] and [B] for the number of trips detected.

    7. Enter the following menus: Powertrain / Engine and ECT / Trouble Codes.

    8. Confirm that the DTC is not output again.


    NEXT