СИСТЕМА SFI (для моделей без системы РОГ), 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

When the engine misfires, high concentrations of hydrocarbons (HC) enter the exhaust gas. Extremely high hydrocarbon concentration levels can cause an increase in exhaust emission levels. Extremely high concentrations of hydrocarbons can also cause increases in the three-way catalytic converter temperature, which may cause damage to the three-way catalytic converter. To prevent this increase in emissions and to limit the possibility of thermal damage, the ECM monitors the misfire count. When the temperature of the three-way catalytic converter reaches the point of thermal degradation, the ECM blinks the MIL. To monitor misfires, the ECM uses both the camshaft position sensor and the crankshaft position sensor. The camshaft position sensor is used to identify any misfiring cylinders and the crankshaft position sensor is used to measure variations in the crankshaft rotation speed. Misfires are counted when the crankshaft rotation speed variations exceed predetermined thresholds. If the misfire count exceeds the threshold levels, and could cause emission control system performance deterioration, the ECM illuminates the MIL and stores a DTC.

DTC No. DTC Detection Condition Trouble Area
P0300

Simultaneous misfiring of several cylinders occurs and one of the following conditions is met (2 trip detection logic):


  • A misfire occurs that may damage the three-way catalytic converter (MIL blinks when detect immediately).

  • An emission deterioration misfire occurs (MIL illuminates).

  • Open or short in engine wire harness

  • Connector connection

  • Vacuum hose connections

  • Ignition system

  • Fuel injector assembly (for port injection)

  • Fuel injector assembly (for direct injection)

  • Fuel pressure

  • Mass air flow meter sub-assembly

  • Engine coolant temperature sensor

  • Compression pressure

  • Valve timing

  • PCV valve and hose

  • PCV hose connections

  • Intake system

  • ECM

P0301

P0302

P0303

P0304

Misfiring of a specific cylinder occurs and one of the following conditions is met (2 trip detection logic):


  • A misfire occurs that may damage the three-way catalytic converter (MIL blinks when detect immediately).

  • An emission deterioration misfire occurs (MIL illuminates).

  • Open or short in engine wire harness

  • Connector connection

  • Vacuum hose connections

  • Ignition system

  • Fuel injector assembly (for port injection)

  • Fuel injector assembly (for direct injection)

  • Fuel pressure

  • Mass air flow meter sub-assembly

  • Engine coolant temperature sensor

  • Compression pressure

  • Valve timing

  • PCV valve and hose

  • PCV hose connections

  • Intake system

  • ECM

When DTCs for misfiring cylinders are randomly stored, but DTC P0300 is not stored, it indicates that misfires have been detected in different cylinders at different times. DTC P0300 is only stored when several misfiring cylinders are detected at the same time.

MONITOR DESCRIPTION

The ECM illuminates the MIL and stores a DTC when the following condition, which could cause emission deterioration, is detected (2 trip detection logic).


The ECM flashes the MIL (immediate detection logic) and stores a DTC (2 trip detection logic) when the following condition, which could cause damage to the three-way catalytic converter, is detected.


MONITOR STRATEGY

Required Sensors/Components (Main)

Crankshaft position sensor

Camshaft position sensor
Required Sensors/Components (Related)

Engine coolant temperature

Intake air temperature sensor

Mass air flow meter sub-assembly
Frequency of Operation Continuous

TYPICAL ENABLING CONDITIONS

Misfire
Intake air temperature Higher than -10°C (14°F)
Either of the following conditions is met (a) or (b)
(a) Engine coolant temperature at engine start Higher than -7°C (19°F)
(b) Engine coolant temperature Higher than 20°C (68°F)
Monitor Period of Emission-related Misfire
Duration Crankshaft 1000 revolutions x 4
Monitor Period of Catalyst-damaging Misfire (MIL Blinks)
Duration Crankshaft 200 revolutions x 3

CONFIRMATION DRIVING PATTERN


  1. Connect the GTS to the DLC3.

  2. Turn the power switch on (IG).

  3. Turn the GTS on.

  4. Record the DTC(s) and freeze frame data.

  5. Clear the DTCs (even if no DTCs are stored, perform the clear DTC procedure).

  6. Put the engine in inspection mode (maintenance mode) Click here.

  7. Using the GTS, switch the ECM from normal mode to check mode Click here.

  8. Start the engine.

  9. Read the misfire counts of each cylinder, Cylinder #1 Misfire Count to Cylinder #4 Misfire Count, with the engine idling. If any misfire count is displayed, skip the following confirmation driving pattern.

  10. Drive the vehicle so that the vehicle conditions displayed in Misfire RPM and Misfire Load of the Data List are the same as the freeze frame data. Perform this step several times.

    Tech Tips

    In order to store misfire DTCs, it is necessary to operate the vehicle for the period of time shown in the table below, confirm the Misfire RPM and Misfire Load in the Data List.

    Engine Speed Duration
    Idling 4.5 minutes or more
    1000 4.5 minutes or more
    2000 2.5 minutes or more
    3000 1.5 minutes or more

  11. Check whether misfires have occurred by checking DTCs and freeze frame data.

    Tech Tips

    Do not turn the power switch off until the output DTC(s) and freeze frame data have been recorded. When the ECM returns to normal mode (default), the stored DTC(s), freeze frame data and other data are cleared.

  12. Record the DTC(s), freeze frame data and misfire counts.

  13. Turn the power switch off and wait for at least 30 seconds.

  14. Clear the DTCs (even if no DTCs are stored, perform the clear DTC procedure).

WIRING DIAGRAM

Refer to DTC P0102 for the mass air flow meter sub-assembly circuit Click here.

INSPECTION PROCEDURE

Note

Inspect the fuses for circuits related to this system before performing the following procedure.

Tech Tips


  • If any DTCs other than misfire DTCs are output, troubleshoot those DTCs first.

  • Read freeze frame data using the GTS. The ECM records vehicle and driving condition information as freeze frame data the moment a DTC is stored. When troubleshooting, freeze frame data can help determine if the vehicle was moving or stationary, if the engine was warmed up or not, if the air fuel ratio was lean or rich, and other data from the time the malfunction occurred.

  • If the misfire does not recur when the vehicle is brought to the workshop, reproduce the conditions stored in the ECM as freeze frame data.

  • If the misfire still cannot be reproduced even though the conditions stored in the ECM as freeze frame data have been reproduced, one of the following factors is considered to be a possible cause of the problem:


    1. There was insufficient fuel in the tank.

    2. Improper fuel was used.

    3. The spark plugs have been contaminated.

    4. The problem requires further diagnosis.

  • After finishing repairs, check the misfire counts of the cylinders (Cylinder #1 Misfire Count to Cylinder #4 Misfire Count).

  • Be sure to confirm that no misfiring cylinder DTCs are stored again by conducting the confirmation driving pattern after finishing repairs.

  • When one of Short #1 or Long #1 in the freeze frame data is outside the range of +/-20%, the air fuel ratio may be rich (-20% or less) or lean (+20% or higher).

  • When Coolant Temp in the freeze frame data is less than 75°C (167°F), the misfires have occurred only while warming up the engine.

  • An extremely imbalanced drive wheel which causes body vibration may cause misfire DTCs to be stored.

PROCEDURE


  1. CHECK ANY OTHER DTCS OUTPUT (IN ADDITION TO MISFIRE DTCS)


    1. Connect the GTS to the DLC3.

    2. Turn the power switch on (IG).

    3. Turn the GTS on.

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

    5. Read the DTCs.

      Result
      Result Proceed to
      DTC P0300, P0301, P0302, P0303 and/or P0304 are 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 PCV HOSE CONNECTIONS


    1. Check the PCV hose connections Click here.

      OK
      PCV valve and hose are correctly connected and are not damaged.

    NG

    REPAIR OR REPLACE PCV HOSE

    OK

  3. READ VALUE USING GTS (MISFIRE RPM AND MISFIRE LOAD)


    1. Connect the GTS to the DLC3.

    2. Turn the power switch on (IG).

    3. Turn the GTS on.

    4. Enter the following menus: Powertrain / Engine and ECT / Data List / All Data / Misfire RPM and Misfire Load.

    5. Read and note the Misfire RPM and Misfire Load values.

      Tech Tips

      The Misfire RPM and Misfire Load values indicate the vehicle conditions under which the misfire occurred.


    NEXT

  4. CHECK MISFIRE COUNT OF PORT INJECTION


    1. Connect the GTS to the DLC3.

    2. Turn the power switch on (IG).

    3. Turn the GTS on.

    4. Put the engine in inspection mode (maintenance mode) Click here.

    5. Start the engine and warm it up.

    6. Enter the following menus: Powertrain / Engine and ECT / Active Test / Control the Injection Way / Port / All Data / Injection Way and Cylinder #1 Misfire Count to Cylinder #4 Misfire Count.

    7. Allow the engine to idle.

    8. Read each value for Cylinder #1 Misfire Count to Cylinder #4 Misfire Count and Injection Way displayed on the GTS. If no misfire counts occur in any cylinders, perform procedure [A] and [B] and then check the misfire counts again.

    9. Drive the vehicle with the Misfire RPM and Misfire Load noted in the "Read Value Using GTS (Misfire RPM and Misfire Load)" procedures above [A].

    10. Read the Injection Way and Cylinder #1 Misfire Count to Cylinder #4 Misfire Count or DTCs displayed on the GTS [B].

      Result
      Injection Way Misfire count Proceed to
      Port 1 or 2 cylinders have misfire counts A
      3 cylinders or more have misfire counts A
      There are no misfire counts B

    B

    CHECK MISFIRE COUNT OF DIRECT INJECTION Click here

    A

  5. CHECK MISFIRE COUNT OF DIRECT INJECTION


    1. Connect the GTS to the DLC3.

    2. Turn the power switch on (IG).

    3. Turn the GTS on.

    4. Put the engine in inspection mode (maintenance mode) Click here.

    5. Start the engine and warm it up.

    6. Enter the following menus: Powertrain / Engine and ECT / Active Test / Control the Injection Way / Direct / All Data / Injection Way and Cylinder #1 Misfire Count to Cylinder #4 Misfire Count.

    7. Allow the engine to idle.

    8. Read each value for Cylinder #1 Misfire Count to Cylinder #4 Misfire Count and Injection Way displayed on the GTS. If no misfire counts occur in any cylinders, perform procedure [A] and [B] and then check the misfire counts again.

    9. Drive the vehicle with the Misfire RPM and Misfire Load noted in the "Read Value Using GTS (Misfire RPM and Misfire Load)" procedures above [A].

    10. Read the Injection Way and Cylinder #1 Misfire Count to Cylinder #4 Misfire Count or DTCs displayed on the GTS [B].

      Result
      Misfire count Proceed to
      Port (Result of Step 4) Direct
      1 or 2 cylinders have misfire counts There are no misfire counts A
      3 cylinders or more have misfire counts There are no misfire counts B
      1 or 2 cylinders have misfire counts 1 or 2 cylinders have misfire counts C
      3 cylinders or more have misfire counts 3 cylinders or more have misfire counts D

      Tech Tips

      Perform "Inspection After Repair" after replacing the fuel injector assembly (for port injection) Click here.


    B

    CHECK FUEL PRESSURE (FOR LOW PRESSURE) Click here

    C

    INSPECT SPARK PLUG Click here

    D

    CHECK INTAKE SYSTEM Click here

    A

    REPLACE FUEL INJECTOR ASSEMBLY (FOR PORT INJECTION (MISFIRING CYLINDER)) Click here

  6. CHECK FUEL PRESSURE (FOR LOW PRESSURE)


    1. Check the fuel pressure (for low pressure) Click here.

      Tech Tips

      Perform "Inspection After Repair" after replacing the fuel injector assembly (for port injection) Click here.


    NG

    CHECK FUEL PUMP OPERATION (FOR LOW PRESSURE) Click here

    OK

    REPLACE FUEL INJECTOR ASSEMBLY (FOR PORT INJECTION (MISFIRING CYLINDER)) Click here

  7. CHECK FUEL PUMP OPERATION (FOR LOW PRESSURE)


    1. Check the fuel pump operation Click here.

      Tech Tips

      Perform "Inspection After Repair" after replacing the fuel pump (for low pressure) Click here.


    NG

    REPLACE FUEL PUMP (FOR LOW PRESSURE) Click here

    OK

    CHECK AND REPLACE FUEL SYSTEM (PRESSURE REGULATOR, PIPE LINE AND FILTER)

  8. CHECK MISFIRE COUNT OF DIRECT INJECTION


    1. Connect the GTS to the DLC3.

    2. Turn the power switch on (IG).

    3. Turn the GTS on.

    4. Put the engine in inspection mode (maintenance mode) Click here.

    5. Start the engine and warm it up.

    6. Enter the following menus: Powertrain / Engine and ECT / Active Test / Control the Injection Way / Direct / All Data / Injection Way and Cylinder #1 Misfire Count to Cylinder #4 Misfire Count.

    7. Allow the engine to idle.

    8. Read each value for Cylinder #1 Misfire Count to Cylinder #4 Misfire Count and Injection Way displayed on the GTS. If no misfire counts occur in any cylinders, perform procedure [A] and [B] and then check the misfire counts again.

    9. Drive the vehicle with the Misfire RPM and Misfire Load noted in the "Read Value Using GTS (Misfire RPM and Misfire Load)" procedures above [A].

    10. Read the Injection Way and Cylinder #1 Misfire Count to Cylinder #4 Misfire Count or DTCs displayed on the GTS [B].

      Result
      Misfire count Proceed to
      Port (Result of Step 4) Direct
      There are no misfire counts There are misfire counts A
      There are no misfire counts There are no misfire counts B

      Tech Tips

      Perform "Inspection After Repair" after replacing the fuel injector assembly (for direct injection) Click here.


    B

    CHECK MISFIRE COUNT Click here

    A

    REPLACE FUEL INJECTOR ASSEMBLY (FOR DIRECT INJECTION (MISFIRING CYLINDER)) Click here

  9. CHECK MISFIRE COUNT


    1. Connect the GTS to the DLC3.

    2. Turn the power switch on (IG).

    3. Turn the GTS on.

    4. Clear the DTCs.

    5. Put the engine in inspection mode (maintenance mode) Click here.

    6. Start the engine and warm it up.

    7. Enter the following menus: Powertrain / Engine and ECT / Data List / Misfire RPM, Misfire Load, Cylinder #1 to #4 Misfire Count and Injection Way.

    8. Drive the vehicle with Misfire RPM and Misfire Load.

    9. Monitor all of the misfire count values or DTCs and Injection Way displayed on the GTS.

      Result
      Misfire count Injection Way Proceed to
      There are no misfire counts - A
      1 or 2 cylinders have misfire counts Either B
      3 cylinders or more have misfire counts Either C
      There are misfire counts Direct D

      Tech Tips

      Perform "Inspection After Repair" after replacing the fuel injector assembly (for direct injection) Click here.


    B

    INSPECT SPARK PLUG Click here

    C

    CHECK INTAKE SYSTEM Click here

    D

    REPLACE FUEL INJECTOR ASSEMBLY (FOR DIRECT INJECTION (MISFIRING CYLINDER)) Click here

    A

    CHECK FOR INTERMITTENT PROBLEMS Click here

  10. INSPECT SPARK PLUG


    1. Inspect the spark plug of the misfiring cylinder Click here.

      Tech Tips

      Perform "Inspection After Repair" after replacing the spark plug Click here.


    NG

    REPLACE SPARK PLUG Click here

    OK

  11. CHECK FOR SPARK (SPARK TEST)


    1. Perform a spark test Click here.

      Tech Tips


      • If the result of the spark test is normal, proceed to the next step.

      • Perform "Inspection After Repair" after replacing the spark plug or ignition coil assembly Click here.


    NEXT

  12. CHECK CYLINDER COMPRESSION PRESSURE


    1. Measure the cylinder compression pressure of the misfiring cylinder Click here.

      Tech Tips

      Perform "Inspection After Repair" after repairing or replacing the engine assembly Click here.


    NG

    CHECK ENGINE TO DETERMINE CAUSE OF LOW COMPRESSION

    OK

    REPLACE ECM Click here

  13. CHECK INTAKE SYSTEM


    1. Check the intake system for vacuum leaks Click here.

      OK
      No leaks from intake system.

      Tech Tips

      Perform "Inspection After Repair" after repairing or replacing the intake system Click here.


    NG

    REPAIR OR REPLACE INTAKE SYSTEM

    OK

  14. READ VALUE USING GTS (COOLANT TEMP)


    1. Connect the GTS to the DLC3.

    2. Turn the power switch on (IG).

    3. Turn the GTS on.

    4. Enter the following menus: Powertrain / Engine and ECT / Data List / All Data / Coolant Temp.

    5. Read the Data List twice, when the engine is both cold and warmed up.

      Standard
      GTS Display Condition Specified Condition
      Coolant Temp Cold engine Same as ambient air temperature
      Warm engine Between 75 and 100°C (167 and 212°F)

      Tech Tips

      Perform "Inspection After Repair" after replacing the engine coolant temperature sensor Click here.


    NG

    REPLACE ENGINE COOLANT TEMPERATURE SENSOR Click here

    OK

  15. READ VALUE USING GTS (MAF)


    1. Connect the GTS to the DLC3.

    2. Turn the power switch on (IG) and turn the GTS on.

    3. Put the engine in inspection mode (maintenance mode) Click here.

    4. Start the engine.

    5. Enter the following menus: Powertrain / Engine and ECT / Data List / All Data / MAF, Coolant Temp and Engine Speed.

    6. Allow the engine to idle until Coolant Temp reaches 75°C (167°F) or higher.

    7. Read MAF with the engine speed at 2500 rpm.

      Tech Tips

      During charging control, the engine speed is set at idle. Therefore, the engine speed does not increase when depressing the accelerator pedal. In this case, read the Data List after charging control has completed.

      Standard
      GTS Display Condition Specified Condition
      MAF

      Shift lever position: P

      A/C: Off

      Engine Speed: 2500 rpm

      		 Between 6.0 gm/sec and 11.0 gm/sec

    NG

    CHECK HARNESS AND CONNECTOR (MASS AIR FLOW METER SUB-ASSEMBLY CONNECTOR CONNECTION) Click here

    OK

  16. CHECK VALVE TIMING (CHECK FOR LOOSE TIMING CHAIN AND JUMPED TEETH)


    1. Remove the cylinder head cover sub-assembly.

      A01FUQPE01
      Text in Illustration
      *a Timing Mark *b 7.43°
      *c 32.45° - -

    2. Turn the crankshaft pulley and align its groove with the "0" timing mark of the timing chain cover.

    3. Check that the timing marks of the camshaft timing gear assembly and camshaft timing exhaust gear assembly are at the positions shown in the illustration.

      Tech Tips

      If the timing marks are not as shown, turn the crankshaft one revolution clockwise.

      OK
      Timing marks on camshaft timing gear assembly and camshaft timing exhaust gear assembly are aligned as shown in the illustration.

    NG

    ADJUST VALVE TIMING Click here

    OK

  17. CHECK HARNESS AND CONNECTOR (MASS AIR FLOW METER SUB-ASSEMBLY CONNECTOR CONNECTION)


    1. Check the connection and terminal contact pressure of connectors and wire harnesses between the mass air flow meter sub-assembly and ECM Click here.

      Tech Tips

      Repair any problems.


    NEXT

  18. CHECK WHETHER DTC OUTPUT RECURS (MISFIRE DTCS)


    1. Connect the GTS to the DLC3.

    2. Turn the power switch on (IG).

    3. Turn the GTS on.

    4. Clear the DTCs.

    5. Turn the power switch off and wait for at least 30 seconds.

    6. Turn the power switch on (IG).

    7. Turn the GTS on.

    8. Drive the vehicle in accordance with the driving pattern described in Confirmation Driving Pattern.

    9. Enter the following menus: Powertrain / Engine and ECT / Utility / All Readiness.

    10. Input the DTC: P0300, P0301, P0302, P0303 or P0304.

    11. Check the DTC judgment result.

      Result
      Result Proceed to

      ABNORMAL

      (DTC P0300, P0301, P0302, P0303 and/or P0304 is output)

      		 A

      NORMAL

      (DTCs are not output)

      		 B

    B

    END

    A

  19. CHECK HARNESS AND CONNECTOR (MASS AIR FLOW METER SUB-ASSEMBLY - ECM)


    1. Disconnect the mass air flow meter sub-assembly connector.

    2. Disconnect the ECM connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      F39-5 (VG) - F70-91 (VG) Always Below 1 Ω
      F39-4 (E2G) - F70-92 (E2G) Always Below 1 Ω
      F39-5 (VG) or F70-91 (VG) - Body ground Always 10 kΩ or higher

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  20. REPLACE MASS AIR FLOW METER SUB-ASSEMBLY


    1. Replace the mass air flow meter sub-assembly Click here.

      Tech Tips


      • If the results of the inspections performed in step 15 indicated no problem, proceed to the next step without replacing the mass air flow meter sub-assembly.

      • Perform "Inspection After Repair" after replacing the mass air flow meter subassembly Click here.


    NEXT

  21. CONFIRM WHETHER MALFUNCTION HAS BEEN SUCCESSFULLY REPAIRED


    1. Connect the GTS to the DLC3.

    2. Turn the power switch on (IG).

    3. Turn the GTS on.

    4. Clear the DTCs.

    5. Turn the power switch off and wait for at least 30 seconds.

    6. Turn the power switch on (IG).

    7. Turn the GTS on.

    8. Drive the vehicle in accordance with the driving pattern described in Confirmation Driving Pattern.

    9. Enter the following menus: Powertrain / Engine and ECT / Utility / All Readiness.

    10. Input the DTC: P0300, P0301, P0302, P0303 or P0304.

    11. Check the DTC judgment result.

      Result
      Result Proceed to

      NORMAL

      (DTCs are not output)

      		 A

      ABNORMAL

      (DTC P0300, P0301, P0302, P0303 and/or P0304 is output)

      		 B

    B

    REPLACE ECM Click here

    A

    END