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

  • If DTC P0301 is displayed, check the No. 1 cylinder.

  • If DTC P0302 is displayed, check the No. 2 cylinder.

  • If DTC P0303 is displayed, check the No. 3 cylinder.

  • If DTC P0304 is displayed, check the No. 4 cylinder.

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.

Tip:

  • 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
Table 1. DTC Detection Drive Pattern

DTC No.

DTC Detection Drive Pattern

P0300

Idling with warm engine for 10 minutes or more

P0301

P0302

P0303

P0304
Tip:

  • 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

Tip:

  • 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
      Tip:

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

    B

    GO TO DTC CHART

    Click hereClick hereClick 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 CODEClick 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 CONNECTORClick 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.

      Tip:

      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.

      Tip:

      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.

      Tip:

      • 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.

      Tip:

      • 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 hereClick here

      OK

      The cylinder compression pressure is within the standard range.

    Result

    Proceed to

    OK

    NG
    NG

    CHECK ENGINE TO DETERMINE CAUSE OF LOW COMPRESSIONClick 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 CLEARANCEClick 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.

      Tip:

      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 hereClick here

    Result

    Proceed to

    NEXT
    NEXT

    CONFIRM WHETHER MALFUNCTION HAS BEEN SUCCESSFULLY REPAIREDClick here

  12. REPAIR OR REPLACE HARNESS OR CONNECTOR

    Result

    Proceed to

    NEXT
    NEXT

    CONFIRM WHETHER MALFUNCTION HAS BEEN SUCCESSFULLY REPAIREDClick here

  13. REGISTER INJECTOR COMPENSATION CODE

    1. Register the injector compensation code.

      Click here

    Result

    Proceed to

    NEXT
    NEXT

    CONFIRM WHETHER MALFUNCTION HAS BEEN SUCCESSFULLY REPAIREDClick here

  14. ADJUST VALVE CLEARANCE

    1. Adjust the valve clearance.

      Click here

    Result

    Proceed to

    NEXT
    NEXT

    CONFIRM WHETHER MALFUNCTION HAS BEEN SUCCESSFULLY REPAIREDClick 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.

      Tip:

      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