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СИСТЕМА SFI, Diagnostic DTC:P0300, P0301, P0302, P0303, P0304

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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
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DESCRIPTION

Table 1. Text in Illustration
*1 Camshaft Position Sensor
*2 Crankshaft Position Sensor
*3 ECM

When the engine misfires, high concentrations of hydrocarbons (HC) enter the exhaust gas. Extremely high HC concentration levels can cause increases in exhaust emissions levels. High concentrations of HC can also cause increases in the Three-way Catalytic Converter (TWC) temperature, which may cause damage to the Three-way Catalytic Converter (TWC). To prevent these increases in emissions and to limit the possibility of thermal damage, the ECM monitors the misfire rate. When the temperature of the Three-way Catalytic Converter (TWC) reaches the point of thermal degradation, the MIL blinks. 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 as when the crankshaft rotation speed variations exceed predetermined thresholds.

If the misfire rate exceeds the threshold, 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 below is detected (2 trip detection logic):


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

  • Catalyst deterioration misfire occurs (MIL illuminates).

  • Open or short in engine wire harness

  • Connector connection

  • Vacuum hose connections

  • Ignition system

  • Fuel injector assembly

  • Fuel pressure

  • Mass air flow meter

  • Engine coolant temperature sensor

  • Compression pressure

  • Valve timing

  • PCV valve and hose

  • PCV hose connections

  • Intake system

  • ECM

P0301

P0302

P0303

P0304

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


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

  • Catalyst deterioration misfire occurs (MIL illuminates).

When multiple DTCs for misfiring cylinders are 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.

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MONITOR DESCRIPTION

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


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


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MONITOR STRATEGY

Required Sensors/Components (Main) Crankshaft position sensor and camshaft position sensor
Required Sensors/Components (Related) Engine coolant temperature, intake air temperature sensors and mass air flow meter
Frequency of Operation Continuous
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TYPICAL ENABLING CONDITIONS

Table 2. Misfire
Intake air temperature Higher than -10°C (14°F)
Either of following conditions (a) or (b) met -
(a) Engine coolant temperature at engine start Higher than -7°C (19°F)
(b) Engine coolant temperature Higher than 20°C (68°F)
Table 3. Monitor Period of Emissions-related Misfire
Duration 1000 crankshaft revolutions x 4
Table 4. Monitor Period of Catalyst-damaging Misfire (MIL Blinks)
Duration 200 crankshaft revolutions x 3
A003GW8E01
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WIRING DIAGRAM

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CONFIRMATION DRIVING PATTERN


  1. Connect the intelligent tester to the DLC3.

  2. Turn the ignition switch to ON.

  3. Turn the intelligent tester on.

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

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

  6. Using the intelligent tester, switch the ECM from normal mode to check mode (Click here).

  7. Read the misfire counts of each cylinder (cylinder No. 1 to No. 4) with the engine idling. If any misfire count is displayed, skip the following confirmation driving pattern.

  8. Drive the vehicle several times with the conditions, such as engine speed and engine load, as shown in Misfire RPM and Misfire Load in the freeze frame data.

    Tip:

    In order to store misfire DTCs, it is necessary to operate the vehicle for the period of time shown in the table below with the engine speed and engine load the same as Misfire RPM and Misfire Load in the freeze frame data.

    Engine Speed Duration
    Idling 8.0 minutes or more
    1000 4.5 minutes or more
    2000 2.5 minutes or more
    3000 1.5 minutes or more

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

    Tip:

    Do not turn the ignition switch off until the stored DTCs and freeze frame data have been recorded. When the ECM returns to normal mode (default), the stored DTCs, freeze frame data and other data will be cleared.

  10. Record the DTCs, freeze frame data and misfire counts.

  11. Turn the ignition switch off and wait for at least 30 seconds.

  12. Clear the DTCs (even if no DTCs are stored, perform the clear DTC operation).

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INSPECTION PROCEDURE

Tip:

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

  • 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, if the air-fuel ratio was lean or rich, and other data from the time the malfunction occurred.

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


    1. The fuel level is low.

    2. Improper fuel is being used.

    3. The spark plugs are dirty.

  • After finishing repairs, check that no misfires occur in each cylinder (cylinder No. 1, No. 2, No. 3 and No. 4).

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

  • When one of Short FT #1 or Long FT #1 in the freeze frame data is outside the range of +/-15%, the air-fuel ratio may be rich (-15% or less) or lean (+15% or more).

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

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

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PROCEDURE


  1. Click here

    CHECK FOR ANY OTHER DTCS OUTPUT (IN ADDITION TO MISFIRE CODES)


    1. Connect the intelligent tester to the DLC3.

    2. Turn the ignition switch to ON.

    3. Turn the intelligent tester on.

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

    5. Read the DTCs.

      Table 5. Result
      Result Proceed to
      P0300, P0301, P0302, P0303 and/or P0304 is output A
      P0300, P0301, P0302, P0303 and/or P0304 and other DTCs are output B
      Tip:

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


  2. Click here

    CHECK PCV HOSE CONNECTIONS


    1. Check the PCV hose connections (Click here).

      OK
      PCV hose is connected correctly and is not damaged.

  3. Click here

    READ VALUE USING INTELLIGENT TESTER (MISFIRE RPM AND MISFIRE LOAD)


    1. Connect the intelligent tester to the DLC3.

    2. Turn the ignition switch to ON.

    3. Turn the intelligent tester 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.

      Tip:

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


  4. Click here

    READ VALUE USING INTELLIGENT TESTER (MISFIRE COUNT)


    1. Connect the intelligent tester to the DLC3.

    2. Turn the ignition switch to ON.

    3. Turn the intelligent tester on.

    4. Clear the DTCs (Click here).

    5. Enter the following menus: Powertrain / Engine and ECT / Data List / All Data / Cylinder #1 Misfire Count, #2, #3 and #4.

    6. Allow the engine to idle.

    7. Read the values for Cylinder #1 Misfire Count to Cylinder #4 Misfire Count displayed on the intelligent tester. If no misfire counts occur in any cylinders, perform the following procedures:


      1. Check Cylinder #1 Misfire Count to Cylinder #4 Misfire Count.

      2. If misfire counts are still not displayed, perform procedures "A" and "B", and then check the misfire counts again.

        Procedure A: Drive the vehicle while matching the vehicle conditions to the Misfire RPM and Misfire Load values noted in the "Read Value Using Intelligent Tester (Misfire RPM and Misfire Load)" procedure above.

        Procedure B: Read Cylinder #1 Misfire Count to Cylinder #4 Misfire Count or the DTCs output on the intelligent tester.

        Table 6. Result
        Result Proceed to
        Most misfires occur in only 1 or 2 cylinders A
        3 cylinders or more have equal misfire counts B
        Tip:

        • If it is difficult to reproduce misfires for each cylinder, check the Data List item called Misfire Margin. Try to find vehicle driving conditions that lower the Misfire Margin value. Values above 30% are considered normal.

        • If the freeze frame data's record of the engine coolant temperature is below 75°C (167°F), misfire may be detected only when the engine is cold.

        • If the freeze frame data's record of the Engine Run Time is less than 120 seconds, misfire may be detected immediately after the engine is started.


  5. Click here

    INSPECT SPARK PLUG


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


  6. Click here

    CHECK FOR SPARK (SPARK TEST)


    1. Perform a spark test (Click here).

      Tip:

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


  7. Click here

    CHECK CYLINDER COMPRESSION PRESSURE


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


  8. Click here

    CHECK FUEL INJECTOR ASSEMBLY (POWER SOURCE)


    1. Disconnect the fuel injector connector.

    2. Turn the ignition switch to ON.

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

      Standard Voltage
      Cylinder Tester Connection Switch Condition Specified Condition
      No. 1 D24-1 - Body ground Ignition switch ON 11 to 14 V
      No. 2 D25-1 - Body ground Ignition switch ON 11 to 14 V
      No. 3 D26-1 - Body ground Ignition switch ON 11 to 14 V
      No. 4 D27-1 - Body ground Ignition switch ON 11 to 14 V
      Table 7. Text in Illustration
      *a

      Front view of wire harness connector

      (to Fuel Injector Assembly)

  9. Click here

    CHECK HARNESS AND CONNECTOR (FUEL INJECTOR - ECM)


    1. Disconnect the fuel injector connector.

    2. Disconnect the ECM connector.

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

      Standard Resistance
      Cylinder Tester Connection Condition Specified Condition
      No. 1 D24-2 - Body ground Always 10 kΩ or higher
      D24-2 - D97-86 (#1) Always Below 1 Ω
      No. 2 D25-2 - Body ground Always 10 kΩ or higher
      D25-2 - D97-85 (#2) Always Below 1 Ω
      No. 3 D26-2 - Body ground Always 10 kΩ or higher
      D26-2 - D97-84 (#3) Always Below 1 Ω
      No. 4 D27-2 - Body ground Always 10 kΩ or higher
      D27-2 - D97-83 (#4) Always Below 1 Ω

  10. Click here

    CHECK FUEL INJECTOR ASSEMBLY OF MISFIRING CYLINDER


    1. Check the fuel injector injection [whether fuel volume is high or low, and whether injection pattern is poor] (Click here).


  11. Click here

    CHECK INTAKE SYSTEM


    1. Check the intake system for vacuum leakage.

      OK
      No leakage in intake system.

  12. Click here

    CHECK FUEL PRESSURE


    1. Check the fuel pressure (Click here).


  13. Click here

    READ VALUE USING INTELLIGENT TESTER (COOLANT TEMP)


    1. Connect the intelligent tester to the DLC3.

    2. Turn the ignition switch to ON.

    3. Turn the intelligent tester on.

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

    5. Read Coolant Temp twice, when the engine is both cold and warmed up.

      Standard
      With cold engine: Same as ambient air temperature.
      With warm engine: Between 75°C and 100°C (167°F and 212°F).

  14. Click here

    READ VALUE USING INTELLIGENT TESTER (MAF)


    1. Connect the intelligent tester to the DLC3.

    2. Turn the ignition switch to ON.

    3. Turn the intelligent tester on.

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

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

    6. Read MAF with the engine speed at 3000 rpm.

      Standard
      Between 6 gm/sec and 18 gm/sec (shift lever: N; A/C: Off).

  15. Click here

    CHECK VALVE TIMING


    1. Remove the cylinder head cover.

    2. Turn the crankshaft to align the timing marks of the crankshaft.

    3. Align the groove of the crankshaft pulley with the "0" position.

    4. Confirm whether the timing marks of the camshaft pulley and cylinder head cover are facing each other.

      Tip:

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

      OK
      The timing marks of the camshaft pulley and the cylinder head cover face each other when the groove of the crankshaft pulley is in the "0" position.
      Table 8. Text in Illustration
      *1 Timing Mark

  16. Click here

    CHECK INTAKE SYSTEM


    1. Check the intake system for vacuum leakage.

      OK
      No leakage in intake system.

  17. Click here

    CHECK FUEL PRESSURE


    1. Check the fuel pressure (Click here).


  18. Click here

    READ VALUE USING INTELLIGENT TESTER (COOLANT TEMP)


    1. Connect the intelligent tester to the DLC3.

    2. Turn the ignition switch to ON.

    3. Turn the intelligent tester on.

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

    5. Read Coolant Temp twice, when the engine is both cold and warmed up.

      Standard
      With cold engine: Same as ambient air temperature.
      With warm engine: Between 75°C and 100°C (167°F and 212°F).

  19. Click here

    READ VALUE USING INTELLIGENT TESTER (MAF)


    1. Connect the intelligent tester to the DLC3.

    2. Turn the ignition switch to ON.

    3. Turn the intelligent tester on.

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

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

    6. Read MAF with the engine speed at 3000 rpm.

      Standard
      Between 6 gm/sec and 18 gm/sec (shift lever: N; A/C: Off).

  20. Click here

    CHECK VALVE TIMING


    1. Remove the cylinder head cover.

    2. Turn the crankshaft to align the timing marks of the crankshaft.

    3. Align the groove of the crankshaft pulley with the "0" position.

    4. Confirm whether the timing marks of the camshaft pulley and cylinder head cover are facing each other.

      Tip:

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

      OK
      The timing marks of the camshaft pulley and the cylinder head cover face each other when the groove of the crankshaft pulley is in the "0" position.
      Table 9. Text in Illustration
      *1 Timing Mark

  21. Click here

    INSPECT SPARK PLUG


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


  22. Click here

    CHECK FOR SPARK (SPARK TEST)


    1. Perform a spark test (Click here).

      Tip:

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


  23. Click here

    CHECK CYLINDER COMPRESSION PRESSURE


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


  24. Click here

    CHECK FUEL INJECTOR ASSEMBLY (POWER SOURCE)


    1. Disconnect the fuel injector connector.

    2. Turn the ignition switch to ON.

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

      Standard Voltage
      Cylinder Tester Connection Switch Condition Specified Condition
      No. 1 D24-1 - Body ground Ignition switch ON 11 to 14 V
      No. 2 D25-1 - Body ground Ignition switch ON 11 to 14 V
      No. 3 D26-1 - Body ground Ignition switch ON 11 to 14 V
      No. 4 D27-1 - Body ground Ignition switch ON 11 to 14 V
      Table 10. Text in Illustration
      *a

      Front view of wire harness connector

      (to Fuel Injector Assembly)

  25. Click here

    CHECK HARNESS AND CONNECTOR (FUEL INJECTOR - ECM)


    1. Disconnect the fuel injector connector.

    2. Disconnect the ECM connector.

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

      Standard Resistance
      Cylinder Tester Connection Condition Specified Condition
      No. 1 D24-2 - Body ground Always 10 kΩ or higher
      D24-2 - D97-86 (#1) Always Below 1 Ω
      No. 2 D25-2 - Body ground Always 10 kΩ or higher
      D25-2 - D97-85 (#2) Always Below 1 Ω
      No. 3 D26-2 - Body ground Always 10 kΩ or higher
      D26-2 - D97-84 (#3) Always Below 1 Ω
      No. 4 D27-2 - Body ground Always 10 kΩ or higher
      D27-2 - D97-83 (#4) Always Below 1 Ω

  26. Click here

    CHECK FUEL INJECTOR ASSEMBLY OF MISFIRING CYLINDER


    1. Check the fuel injector injection [whether fuel volume is high or low, and whether injection pattern is poor] (Click here).


  27. Click here

    CHECK HARNESS AND CONNECTOR


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

      Tip:

      Repair any problems.


  28. Click here

    CHECK WHETHER DTC OUTPUT RECURS


    1. Connect the intelligent tester to the DLC3.

    2. Turn the ignition switch to ON.

    3. Turn the intelligent tester on.

    4. Clear the DTCs (Click here).

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

    6. Turn the ignition switch to ON and turn the intelligent tester on.

    7. Start the engine and warm it up.

    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.

      Table 11. Result
      Result Proceed to

      ABNORMAL

      (P0300, P0301, P0302, P0303 or P0304 is output)

      		 A

      NORMAL

      (No DTC is output)

      		 B

  29. Click here

    CHECK HARNESS AND CONNECTOR (MASS AIR FLOW METER - ECM)


    1. Disconnect the mass air flow meter 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
      A3-3 (VG) - D97-69 (VG) Always Below 1 Ω
      A3-2 (E2G) - D97-92 (E2G) Always Below 1 Ω
      A3-3 (VG) or D97-69 (VG) - Body ground Always 10 kΩ or higher

  30. Click here

    REPLACE MASS AIR FLOW METER


    1. Replace the mass air flow meter (Click here).

      Tip:

      If the results of the inspections performed in steps 14 and 19 indicated no problem, proceed to the next step without replacing the mass air flow meter.


  31. Click here

    CONFIRM WHETHER MALFUNCTION HAS BEEN SUCCESSFULLY REPAIRED


    1. Connect the intelligent tester to the DLC3.

    2. Turn the ignition switch to ON.

    3. Turn the intelligent tester on.

    4. Clear the DTCs (Click here).

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

    6. Turn the ignition switch to ON and turn the intelligent tester on.

    7. Start the engine and warm it up.

    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.

      Table 12. Result
      Result Proceed to

      NORMAL

      (No DTC is output)

      		 A

      ABNORMAL

      (P0300, P0301, P0302, P0303 or P0304 is output)

      		 B

  32. Click here

    CHECK FUEL LINE


    1. Check the fuel lines for leaks or blockage.


  33. Click here

    GO TO DTC CHARTClick here

  34. Click here

    REPAIR OR REPLACE PCV HOSEClick here

  35. Click here

    REPLACE SPARK PLUG

  36. Click here

    CHECK ENGINE TO DETERMINE CAUSE OF LOW COMPRESSION

  37. Click here

    GO TO FUEL INJECTOR CIRCUITClick here

  38. Click here

    REPAIR OR REPLACE HARNESS OR CONNECTOR

  39. Click here

    REPLACE FUEL INJECTOR ASSEMBLYClick here

  40. Click here

    REPAIR OR REPLACE INTAKE SYSTEM

  41. Click here

    REPLACE ENGINE COOLANT TEMPERATURE SENSORClick here

  42. Click here

    ADJUST VALVE TIMINGClick here

  43. Click here

    END

  44. Click here

    REPLACE ECMClick here

  45. Click here

    REPAIR OR REPLACE FUEL LINE

  46. Click here

    REPLACE FUEL PUMPClick here