ECD SYSTEM(w/ Glow Plug Controller), Diagnostic DTC:P0300, P0301, P0302, P0303, P0304

DTC Code DTC Name
P0300 Random / Multiple Cylinder Misfire Detected
P0301 Cylinder 1 Misfire Detected
P0302 Cylinder 2 Misfire Detected
P0303 Cylinder 3 Misfire Detected
P0304 Cylinder 4 Misfire Detected

DESCRIPTION


For monitoring misfires, the ECM uses the crankshaft position sensor and camshaft position sensor to monitor changes in the crankshaft rotation for each cylinder.

The ECM counts the number of times the engine speed fluctuation indicates that a misfire has occurred.

And when the misfire rate equals or exceeds the threshold indicating that the engine condition has deteriorated, the ECM illuminates the MIL and stores a DTC.

Tech Tips


  • A cylinder, which has a compensation value for Injection Feedback Val #1, #2, #3 or #4 that varies from the other cylinders, may be malfunctioning.

  • If only DTCs P0300, P0301, P0302, P0303 and/or P0304 are present, an injector assembly mechanical malfunction or insufficient compression has probably occurred. An open or short in the ECM or injector assembly circuit is unlikely.

DTC No. Detection Item DTC Detection Condition Trouble Area MIL Memory
P0300 Random / Multiple Cylinder Misfire Detected

Significant fluctuations in engine speed while idling

(1 trip detection logic)

  • Injector assembly

  • Open or short in engine wire harness

  • Connector connection

  • Compression pressure

  • Valve clearance

  • Valve timing

  • ECM

  • Low quality fuel

  • Injector compensation code

 - DTC stored
P0301 Cylinder 1 Misfire Detected

Significant fluctuations in engine speed while idling

(2 trip detection logic)

  • Injector assembly

  • Open or short in engine wire harness

  • Connector connection

  • Compression pressure

  • Valve clearance

  • Valve timing

  • ECM

  • Low quality fuel

  • Injector compensation code

 Comes on DTC stored
P0302 Cylinder 2 Misfire Detected

Significant fluctuations in engine speed while idling

(2 trip detection logic)

  • Injector assembly

  • Open or short in engine wire harness

  • Connector connection

  • Compression pressure

  • Valve clearance

  • Valve timing

  • ECM

  • Low quality fuel

  • Injector compensation code

 Comes on DTC stored
P0303 Cylinder 3 Misfire Detected

Significant fluctuations in engine speed while idling

(2 trip detection logic)

  • Injector assembly

  • Open or short in engine wire harness

  • Connector connection

  • Compression pressure

  • Valve clearance

  • Valve timing

  • ECM

  • Low quality fuel

  • Injector compensation code

 Comes on DTC stored
P0304 Cylinder 4 Misfire Detected

Significant fluctuations in engine speed while idling

(2 trip detection logic)

  • Injector assembly

  • Open or short in engine wire harness

  • Connector connection

  • Compression pressure

  • Valve clearance

  • Valve timing

  • ECM

  • Low quality fuel

  • Injector compensation code

 Comes on DTC stored
DTC Detection Drive Pattern
DTC No. DTC Detection Drive Pattern
P0300 Idling with warm engine for 10 minutes or more
P0301
P0302
P0303
P0304

Tech Tips


  • If DTC P0300, P0301, P0302, P0303 and/or P0304 is stored, the following symptoms may appear.


    • Rough idle

    • Engine stall

    • Lack of power

CAUTION / NOTICE / HINT

Note

When replacing the ECM and/or injector assembly, perform ECM Initialization and Registration.

Click here

Tech Tips


  • When the ECM must be replaced, before replacing the ECM, perform the "Learning Values Save" function using the GTS. Then after installing a new ECM, perform all of the initialization and registration procedures for the "Learning Values Write" function by following the instructions shown on the GTS display.

  • Read freeze frame data using the GTS. 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 ANY OTHER DTCS OUTPUT (IN ADDITION TO DTC P0300, P0301, P0302, P0303, 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.


      Powertrain > Engine and ECT > Trouble Codes
      Result
      Result Proceed to
      DTC P0300, P0301, P0302, P0303 and/or P0304 is output A
      DTC P0300, P0301, P0302, P0303 and/or P0304 and other DTCs are output B

      Tech Tips

      If any DTCs other than P0300, P0301, P0302, P0303 and/or P0304 are output, troubleshoot those DTCs first.


    B

    GO TO DTC CHART Click here

    A

  2. CHECK INJECTOR COMPENSATION CODE


    1. Check the injector compensation codes.

      Click here

      OK
      The compensation codes stored in the ECM match the compensation codes of the installed injector assemblies.
      Result
      Proceed to
      OK
      NG

    NG

    REGISTER INJECTOR COMPENSATION CODE Click here

    OK

  3. CHECK WIRE HARNESS AND CONNECTORS (ENGINE ROOM)


    1. Check the wire harness and connector connections.

      OK
      The wire harnesses and connectors have been connected securely and there are good connections.
      Result
      Proceed to
      OK
      NG

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR Click here

    OK

  4. READ VALUE USING GTS (INJECTION FEEDBACK VAL #1 TO #4 AND INJECTION VOLUME)


    1. Start the engine and drive the vehicle until the engine coolant temperature reaches 75°C (167°F) or higher.

    2. Allow the engine to idle for 30 seconds or more.

      Tech Tips

      The shift lever should be in neutral, and the A/C switch and all accessory switches should be off.

    3. Connect the GTS to the DLC3.

    4. Turn the GTS on.

    5. Enter the following menus: Powertrain / Engine and ECT / Data List / Injection Feedback Val #1 to #4 and Injection Volume.


      Powertrain > Engine and ECT > Data List
      Tester Display
      Injection Volume
      Injection Feedback Val #1
      Injection Feedback Val #2
      Injection Feedback Val #3
      Injection Feedback Val #4

    6. Read the value.

      Tech Tips

      When read the Data List values, confirm that PM regeneration is not activated (value of "After Injection Period" is 0) by entering the following menus: Powertrain / Engine and ECT / Data List / After Injection Period.

      If PM regeneration is activated (value of "After Injection Period" is not 0), drive the vehicle until the PM regeneration is complete (value of "After Injection Period" becomes 0).

      Standard
      The compensatory injection volume is between -4.9 mm3/st and 4.9 mm3/st.

      Tech Tips


      • If the injection volume is incorrect, the compensatory injection volume is displayed -5.0 mm3/st or less, or 5.0 mm3/st or more.

      • The compensatory injection volume is usually between -2.0 mm3/st and 2.0 mm3/st.

      Result
      Proceed to
      NEXT

    NEXT

  5. PERFORM ACTIVE TEST USING GTS (FUEL CUT FOR IDENTIFYING MALFUNCTIONING CYLINDER)


    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 / Active Test / Control the Select Cylinder Fuel Cut.


      Powertrain > Engine and ECT > Active Test
      Tester Display
      Control the Select Cylinder Fuel Cut

    4. Check the 4 cylinders in sequence to identify a faulty cylinder by performing the Active Test inspection.

      Tech Tips


      • DTCs may be output after this Active Test. Make sure to check for DTCs after this Active Test. If any DTCs are output, make sure to clear them.

        Click here

      • If the engine idle speed does not change when a injector is disabled, the cylinder being tested is malfunctioning.

      • If the cylinder being tested is normal, there will be a significant change in idle speed when the fuel injection is stopped for that cylinder.

      Result
      Proceed to
      NEXT

    NEXT

  6. CHECK CYLINDER COMPRESSION PRESSURE OF MALFUNCTIONING CYLINDER


    1. Check the cylinder compression pressure.

      Click here

      OK
      The cylinder compression pressure is within the standard range.
      Result
      Proceed to
      OK
      NG

    NG

    CHECK ENGINE TO DETERMINE CAUSE OF LOW COMPRESSION Click here

    OK

  7. CHECK VALVE CLEARANCE OF MALFUNCTIONING CYLINDER


    1. Check the valve clearance (Click here ) and the valve timing Click here.

      OK
      The valve clearance and the valve timing are within the standard range.
      Result
      Proceed to
      OK
      NG

    NG

    ADJUST VALVE CLEARANCE Click here

    OK

  8. CHECK WHETHER DTC OUTPUT RECURS (DTC P0300, P0301, P0302, P0303 AND/OR P0304)


    1. Connect the GTS to the DLC3.

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

    3. Clear the DTCs.


      Powertrain > Engine and ECT > Clear DTCs

    4. Turn the ignition switch off and wait for 30 seconds.

    5. Start the engine and allow it to idle until the engine coolant temperature sensor reaches 75°C (167°F) or higher.

    6. Allow the engine to idle for more than 10 minutes.

      Tech Tips

      The shift lever should be in neutral, and the A/C switch and all accessory switches should be off.

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

    8. Read the pending DTCs.


      Powertrain > Engine and ECT > Trouble Codes
      Result
      Result Proceed to
      DTC P0300, P0301, P0302, P0303 and/or P0304 is output A
      DTC is not output B

    B

    CHECK FOR INTERMITTENT PROBLEMS Click here

    A

  9. REPLACE INJECTOR ASSEMBLY


    1. Replace the injector assembly.

      Click here

      Result
      Proceed to
      NEXT

    NEXT

  10. PERFORM REGISTRATION AND INITIALIZATION


    1. Register the injector compensation codes.

      Click here

    2. Perform Pilot Quantity Learning Values Reset.

      Click here

      Result
      Proceed to
      NEXT

    NEXT

  11. BLEED AIR FROM FUEL SYSTEM


    1. Bleed the air from the fuel system.

      Click here

      Result
      Proceed to
      NEXT

    NEXT

    GO TO STEP 16 Click here

  12. REPAIR OR REPLACE HARNESS OR CONNECTOR

    Result
    Proceed to
    NEXT

    NEXT

    GO TO STEP 16 Click here

  13. REGISTER INJECTOR COMPENSATION CODE


    1. Register the injector compensation code.

      Click here

      Result
      Proceed to
      NEXT

    NEXT

    GO TO STEP 16 Click here

  14. ADJUST VALVE CLEARANCE


    1. Adjust the valve clearance.

      Click here

      Result
      Proceed to
      NEXT

    NEXT

    GO TO STEP 16 Click here

  15. CHECK ENGINE TO DETERMINE CAUSE OF LOW COMPRESSION

    Result
    Proceed to
    NEXT

    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.


      Powertrain > Engine and ECT > Clear DTCs

    4. Turn the ignition switch off and wait for 30 seconds.

    5. Start the engine and allow it to idle until the engine coolant temperature sensor reaches 75°C (167°F) or higher.

    6. Allow the engine to idle for more than 10 minutes.

      Tech Tips

      The shift lever should be in neutral, and the A/C switch and all accessory switches should be off.

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

    8. Confirm that the pending DTC is not output again.


      Powertrain > Engine and ECT > Trouble Codes
      Result
      Proceed to
      NEXT

    NEXT

    END