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Home >> Lexus >> 2006 >> GS 430 >> Repair and Diagnosis >> Engine Performance >> System >> Engine Control System (3UZ-FE) >> SFI System >> DTC P0300 Random / Multiple Cylinder Misfire Detected; DTC P0301 Cylinder 1 Misfire Detected; DTC P0302 Cylinder 2 Misfire Detected; DTC P0303 Cylinder 3 Misfire Detected; DTC P0304 Cylinder 4 Misfire Detected; DTC P0305 Cylinder 5 Misfire Detected; DTC P0306 Cylinder 6 Misfire Detected; DTC P0307 Cylinder 7 Misfire Detected; DTC P0308 Cylinder 8 Misfire Detected >> Confirmation Driving Pattern

Confirmation Driving Pattern

  1. Connect the intelligent tester to the CAN VIM. Then connect the CAN VIM to the DLC3.
  2. Record the DTC and freeze frame data.
  3. Set check mode on the intelligent tester (see DTC CHECK / CLEAR  ).
  4. Read the value on the misfire counter for each cylinder when idling. If the value is displayed on the misfire counter, skip the following confirmation driving procedure.
  5. Drive the vehicle several times while using the DATA LIST's MISFIRE RPM and MISFIRE LOAD menu items to keep track of the vehicle's engine speed, load and its surrounding range.

    If you have no intelligent tester, turn the engine switch off after the symptom is simulated once. Then repeat the simulation process.

    HINT:

    In order to force output of the DTC, it is necessary to drive with MISFIRE RPM and MISFIRE LOAD selected in the DATA LIST for the period of time in the chart below. Do not turn the engine switch off. Turning the engine switch off switches the diagnosis system from check mode to normal mode and all DTCs, freeze frame data and other data are erased.

    ENGINE SPEED SPECIFICATIONS

    Engine RPM Time
    Idling 3.5 minutes or more
    1,000 RPM 3 minutes or more
    2,000 RPM 1.5 minutes or more
    3,000 RPM 1 minute or more
  6. Check if a misfire occurs by monitoring DTC output and the freeze frame data. Then, record the DTCs, freeze frame data and misfire counter data.
  7. Turn the engine switch off and wait for at least 5 seconds.

HINT:

  1. CHECK OTHER DTC OUTPUT 
    1. Connect the intelligent tester to the CAN VIM. Then connect the CAN VIM to the DLC3.
    2. Enter the following menus: DIAGNOSIS / ENHANCED OBD II / DTC INFO / CURRENT CODES.
    3. Read the CURRENT CODES.

      Result 

      DIAGNOSTIC TROUBLE CODE CHART

      Display (DTC output) Proceed to
      P0300, P0301, P0302, P0303, P0304, P0305, P0306, P0307 or P0308 A
      P0300, P0301, P0302, P0303, P0304, P0305, P0306, P0307 or P0308 and other DTCs B

    B : GO TO  RELEVANT DTC CHART  

    A : GO TO NEXT STEP. 

  2. CHECK MISFIRE RPM AND MISFIRE LOAD 
    1. Read and note the MISFIRE RPM and the MISFIRE LOAD (engine load) with the DATA LIST.

      HINT:

      The MISFIRE RPM and MISFIRE LOAD displays have vehicle data that can help lead to successful repairs of any misfiring cylinders.

    NEXT 

  3. CHECK CONNECTION OF PCV HOSE 

    OK: 

    PCV hose is connected correctly and is not damaged. 

    NG : REPAIR OR REPLACE PCV HOSE 

    OK : GO TO NEXT STEP. 

  4. CHECK MISFIRE COUNT (CYL #1, #2, #3, #4, #5, #6, #7, #8) 
    1. Clear the DTCs.
    2. Enter the following menus: DIAGNOSIS / ENHANCED OBD II / DATA LIST / MISFIRE.
    3. Allow the engine to idle.
    4. Read the misfire count of the cylinders #1 to #8. If no misfire is counted for all of the cylinders, move the shift lever into the D position and repeat the 2 previous steps.

      If misfires are still not counted, perform the next 2 steps.

    5. Drive the vehicle with MISFIRE RPM and MISFIRE LOAD selected in the DATA LIST.
    6. Read the misfire count of cylinders #1 to #8, or check for any output DTCs.

      Result 

      RESULT PROCEDURE CHART

      Misfire count in each cylinder Proceed to
      1 or 2 cylinders have some misfire counts A
      3 cylinders or more have some misfire counts B

      HINT:

      • 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 ECT is below 75°C (167°F), the misfire may be detected only when the engine is cold.
      • If the freeze frame data's record of the ENGINE RUN TIME is below 120 seconds, the misfire may be detected right after the engine is started.

    B : Go to step   14 

    A : GO TO NEXT STEP. 

  5. PERFORM ACTIVE TEST (FUEL CUT #1 TO #8) 
    1. Allow the engine to idle.
    2. Enter the following menus: DIAGNOSIS / ENHANCED OBD II / ACTIVE TEST / FUEL CUT#1 (to #8).
    3. If a cylinder has a high misfire count, cut fuel to the cylinder. Compare the misfire count of the cylinder before fuel cut and after fuel cut.

      Result 

      MISFIRE MONITOR CYLINDERS SPECIFICATIONS

      Misfire count in each cylinder Proceed to
      Misfire count of the cylinder before fuel cut and after fuel cut are roughly the same A
      Misfire count of the cylinder before fuel cut is lower than after fuel cut B

      HINT:

      If the misfire count of the cylinder before fuel cut and after fuel cut are roughly the same, the cylinder is misfiring.

      If the misfire count of the cylinder before fuel cut is lower than after fuel cut, the cylinder misfires sometimes.

      NOTE: This ACTIVE TEST cannot be performed while the vehicle is being driven.

    B : Go to step   12 

    A : GO TO NEXT STEP. 

  6. INSPECT SPARK PLUG 
    1. Remove the engine cover.
    2. Remove the ignition coil and the spark plug of the misfire cylinder.
    3. Measure the spark plug electrode gap.
      Fig 1: Identifying Ignition Coil And Spark Plug Of Misfire Cylinder
      G04026987Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

      Standard: 

      The electrode gap is 1.0 to 1.3 mm (0.039 to 0.051 in.) 

    4. Check the electrode for carbon deposits.

      Recommended spark plug 

      RECOMMENDED SPARK PLUG SPECIFICATIONS

      Manufacturer Spark Plug Type
      DENSO SK20R11
      NGK IFR6A11
      NOTE: If the electrode gap is larger than the standard, replace the spark plug. Do not adjust the electrode gap.

    NG : REPLACE SPARK PLUG 

    OK : GO TO NEXT STEP. 

  7. CHECK SPARK PLUG 
    1. Disconnect the injector connectors to prevent the engine from starting.
    2. Install the spark plug to the ignition coil.
    3. Attach the spark plug to the cylinder head cover.
    4. Crank the engine for 2 seconds or less and check if a spark occurs.
      Fig 2: Attaching Spark Plug To Cylinder Head Cover
      G04026988Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

      OK: 

      Spark occurs. 

    NG : Go to step   9 

    OK : GO TO NEXT STEP. 

  8. CHECK CYLINDER COMPRESSION PRESSURE ON MISFIRING CYLINDER 
    1. Measure the cylinder compression pressure of the misfiring cylinder.

    OK : Go to step   10 

    NG : CHECK ENGINE TO DETERMINE CAUSE OF LOW COMPRESSION 

  9. CHANGE NORMAL SPARK PLUG AND CHECK SPARK OF MISFIRING CYLINDER 
    1. For inspection purposes, remove the current spark plug and install a normally functioning spark plug.
    2. Perform a spark test.
      CAUTION: Always disconnect each injector connector.
      NOTE: Do not crank the engine for more than 2 seconds.
      1. Install the spark plug to the ignition coil and connect the ignition coil connector.
      2. Disconnect the injector connector.
      3. Ground the spark plug.
      4. Check if a spark occurs while the engine is being cranked.

        OK: 

        Spark jumps across electrode gap. 

    OK : REPLACE SPARK PLUG 

    NG : REPLACE IGNITION COIL (THEN CONFIRM THAT THERE IS NO MISFIRE) 

  10. CHECK ECM (#1, #2, #3, #4, #5, #6, #7, #8 VOLTAGE) 
    1. Turn the engine switch on (IG).
    2. Measure the voltage of the ECM connectors.
      Fig 3: Measuring Voltage Of ECM Connectors
      G04026989Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
      TESTER CONNECTION SPECIFIED CONDITION CHART

      Tester Connection Specified Condition
      E8-15 (#1) - E6-7 (E1) 9 to 14 V
      E6-17 (#2) - E6-7 (E1) 9 to 14 V
      E8-14 (#3) - E6-7 (E1) 9 to 14 V
      E6-16 (#4) - E6-7 (E1) 9 to 14 V
      E8-13 (#5) - E6-7 (E1) 9 to 14 V
      E6-15 (#6) - E6-7 (E1) 9 to 14 V
      E8-12 (#7) - E6-7 (E1) 9 to 14 V
      E6-14 (#8) - E6-7 (E1) 9 to 14 V

    OK : CHECK FUEL INJECTOR OF MISFIRING CYLINDER 

    NG : GO TO NEXT STEP. 

  11. CHECK WIRE HARNESS (INJECTOR - ECM) 
    1. Disconnect the connector of the misfire cylinder and the E6 and E8 ECM connectors.
    2. Turn the engine switch on (IG).
    3. Measure the resistance and voltage of the wire harness side connectors.
      Fig 4: Measuring Resistance And Voltage Of Wire Harness Side Connectors
      G04026990Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

      Standard voltage 

      TESTER CONNECTION SPECIFIED CONDITION CHART

      Cylinder Tester Connection Specified Condition
      No. 1 E12-1 - Ground 11 to 14 V
      No. 2 E38-1 - Ground 11 to 14 V
      No. 3 E13-1 - Ground 11 to 14 V
      No. 4 E36-1 - Ground 11 to 14 V
      No. 5 E16-1 - Ground 11 to 14 V
      No. 6 E31-1 - Ground 11 to 14 V
      No. 7 E21-1 - Ground 11 to 14 V
      No. 8 E29-1 - Ground 11 to 14 V

      Standard resistance 

      STANDARD RESISTANCE CHART

      Cylinder Tester Connection Specified Condition
      No. 1 E12-2 - Ground 10 kΩ or higher
      No. 1 E12-2 - E8-15 (#1) Below 1 Ω
      No. 2 E38-2 - Ground 10 kΩ or higher
      No. 2 E38-2 - E6-17 (#2) Below 1 Ω
      No. 3 E13-2 - Ground 10 kΩ or higher
      No. 3 E13-2 - E8-14 (#3) Below 1 Ω
      No. 4 E36-2 - Ground 10 kΩ or higher
      No. 4 E36-2 - E6-16 (#4) Below 1 Ω
      No. 5 E16-2 - Ground 10 kΩ or higher
      No. 5 E16-2 - E8-13 (#5) Below 1 Ω
      No. 6 E31-2 - Ground 10 kΩ or higher
      No. 6 E31-2 - E6-15 (#6) Below 1 Ω
      No. 7 E21-2 - Ground 10 kΩ or higher
      No. 7 E21-2 - E8-12 (#7) Below 1 Ω
      No. 8 E29-2 - Ground 10 kΩ or higher
      No. 8 E29-2 - E6-14 (#8) Below 1 Ω

    NG : REPAIR OR REPLACE HARNESS AND CONNECTOR 

    OK : GO TO NEXT STEP. 

  12. CHECK FUEL INJECTOR OF MISFIRING CYLINDER 

    NG : REPLACE FUEL INJECTOR 

    OK : GO TO NEXT STEP. 

  13. CHECK VALVE CLEARANCE OF MISFIRING CYLINDER 

    NG : ADJUST VALVE CLEARANCE 

    OK : GO TO NEXT STEP. 

  14. CHECK AIR INDUCTION SYSTEM 

    NG : REPAIR OR REPLACE AIR INDUCTION SYSTEM 

    OK : GO TO NEXT STEP. 

  15. CHECK VALVE TIMING 
    1. Remove the engine cover.
    2. Remove the drive belt.
    3. Remove the timing belt cover LH and RH.
    4. Turn the crankshaft to align the matchmarks of the crankshaft.
    5. Align the notch of the crankshaft pulley with the "0" position.
    6. Confirm whether the matchmarks of the camshaft pulley and cylinder head cover are facing each other.
    7. If the matchmarks are not facing each other, turn the crankshaft clockwise by 360°. Confirm again if the matchmarks are facing each other.
      Fig 5: Identifying Timing Belt Cover LH And RH
      G04026991Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

      OK: 

      The matchmarks of the camshaft pulley and the cylinder head cover face each other when the notch of the crankshaft pulley is in the "0" position. 

    NG : ADJUST VALVE TIMING 

    OK : GO TO NEXT STEP. 

  16. CHECK FUEL PRESSURE 

    NG : CHECK AND REPLACE FUEL PUMP, PRESSURE REGULATOR, FUEL LINE AND FILTER 

    OK : GO TO NEXT STEP. 

  17. READ DATA LIST (COOLANT TEMP) 
    1. Connect the intelligent tester to the CAN VIM. Then connect the CAN VIM to the DLC3.
    2. Enter the following menus: DIAGNOSIS / ENHANCED OBD II / DATA LIST / PRIMARY / COOLANT TEMP.
    3. Read the COOLANT TEMP value when the engine is cold and warmed up.

      Standard: 

      ECT when the engine is cold: Same as ambient temperature 

      ECT when the engine is warmed up: 75 to 95°C (167 to 203°F) 

    NG : REPLACE ENGINE COOLANT TEMPERATURE SENSOR 

    OK : GO TO NEXT STEP. 

  18. READ DATA LIST (MAF) 
    1. Enter the following menus: DIAGNOSIS / ENHANCED OBD II / DATA LIST / PRIMARY / MAF.
    2. Allow the engine to idle until the ECT reaches 75°C (167°F).
    3. Read the MAF value at idle RPM and 3,000 RPM.

      Standard: 

      MAF at idle RPM: 3 to 6 g/s (shift lever is in N position and A/C is OFF) 

      MAF at 3,000 RPM: 11 to 23 g/s (shift lever is in N position and A/C is OFF) 

    NG : REPLACE MASS AIR FLOW METER 

    OK : CHECK FOR INTERMITTENT PROBLEMS