Inspection Procedure

HINT:

• If any DTCs other than misfire DTCs are output, troubleshoot those DTCs first.
• Read freeze frame data using a Techstream. 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 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 is 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 Rate to Cylinder #4 Misfire Rate.
• Be sure to confirm that no misfiring cylinder DTCs are set again by conducting the confirmation driving pattern after finishing repairs.
• When one of Short FT #1, Long FT #1, Short FT #2 or Long FT #2 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 more).
• When the Coolant Temp in the freeze frame data is less than 75°C (167°F), the misfire have occurred only while warming up the engine.

1. CHECK ANY OTHER DTCS OUTPUT (IN ADDITION TO MISFIRE DTCS) 
   1. Connect a Techstream to the DLC3.
   2. Turn the ignition switch to ON.
   3. Turn the tester ON.
   4. Select the following menu items: Powertrain / Engine and ECT / Trouble Codes.
   5. Read DTCs.

      HINT:

      Write down indicated DTCs.

      Result 

      RESULT REFERENCE
      
      

      Result	Proceed to
      P0300, P0301, P0302, P0303 and/or P0304	A
      P0300, P0301, P0302, P0303 and/or P0304 and other DTCs	B

      HINT:

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

   B: Go to DTC CHART  (See DIAGNOSTIC TROUBLE CODE CHART  )

   A: Go to next step 

2. READ VALUE USING TECHSTREAM (MISFIRE RPM AND MISFIRE LOAD) 
   1. Connect a Techstream to the DLC3.
   2. Turn the ignition switch to ON.
   3. Turn the tester ON.
   4. Select the following menu items: Powertrain / Engine and ECT / Data List / Misfire / Misfire RPM and Misfire Load.
   5. Read and note the Misfire RPM and Misfire Load values.

      HINT:

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

3. CHECK PCV HOSE CONNECTIONS 

   OK: 

   PCV hose is correctly connected and is not damaged. 

   NG: REPAIR OR REPLACE PCV HOSE 

   OK: Go to next step 

4. READ VALUE USING TECHSTREAM (CAT OT MF F/C) 
   1. Connect a Techstream to the DLC3.
   2. Turn the ignition switch to ON.
   3. Turn the tester ON.
   4. Select the following menu items: Powertrain / Engine and ECT / Data List / Catalyst OT MF F/C.
   5. Read the value displayed on the tester.

      Result 

      RESULT REFERENCE
      
      

      Data List	Tester Display	Proceed to
      Catalyst OT MF F/C	Avail	A
      	Not Avl	B

   B:  Go to step  6

   A: Go to next step 

5. PERFORM ACTIVE TEST USING TECHSTREAM (PROHIBIT CAT OT FC) 
   1. Connect a Techstream to the DLC3.
   2. Turn the ignition switch to ON.
   3. Turn the tester ON.
   4. Select the following menu items: Powertrain / Engine and ECT / Active Test / Prohibit the Catalyst OT Misfire prevent F/C.
   5. Perform the Active Test.
      NOTE: When performing the Active Test, make sure the vehicle is stopped and either idling or being revved within 3000 rpm.
6. READ VALUE USING TECHSTREAM (CYLINDER #1 MISFIRE RATE, #2, #3 AND #4) 
   1. Select the following menu items: Powertrain / Engine and ECT / Data List / Misfire / Cylinder #1 Misfire Rate, #2, #3 and #4.
   2. Start the engine and allow the engine to idle.
   3. Read each value for Cylinder #1 Misfire Rate to #4 displayed on the tester. If no misfire counts occur in any cylinders, perform steps (d) and (e) and then check the misfire counts again.
   4. Drive the vehicle with the Misfire RPM and Misfire Load noted in the "READ VALUE USING TECHSTREAM (MISFIRE RPM AND MISFIRE LOAD)" procedures above.
   5. Read the Cylinder #1 Misfire Rate to #4 or DTCs displayed on the tester.

      Result 

      RESULT REFERENCE
      
      

      Result (Misfire Count)	Proceed to
      Most misfires occur in only 1 or 2 cylinders	A
      3 cylinders or more have equal 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 immediately after the engine is started.

   B:  Go to step  18

   A: Go to next step 

7. INSPECT SPARK PLUG 
   1. Remove the ignition coil and the spark plug from the misfiring cylinder.
   2. Measure the spark plug electrode gap.

      Standard gap: 

      1.0 to 1.1 mm (0.039 to 0.043 in.) 

   3. Check the electrode for carbon deposits.

      Recommended spark plug: 

      RECOMMENDED SPARK PLUG REFERENCE
      
      

      Manufacturer	Product
      DENSO	SC20HR11

      NOTE: If the electrode gap is larger than standard, replace the spark plug. Do not adjust the electrode gap.
      Fig 1: Identifying Spark Plug Electrode Gap

      Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
   4. Reinstall the ignition coil.

   NG: REPLACE SPARK PLUG  (See REMOVAL )

   OK: Go to next step 

8. CHECK FOR SPARKS AND IGNITION 
   1. Disconnect the injector connectors to prevent the engine from starting.
      CAUTION: Always disconnect all injector connectors.
   2. Remove the ignition coil from the cylinder head.
   3. Install the spark plug onto the ignition coil.
   4. Attach the spark plug assembly to the cylinder head.
   5. Crank the engine for less than 2 seconds and check the spark.
      NOTE: Do not crank the engine for more than 2 seconds.

      OK: 

      Sparks jump across electrode gap. 

      Fig 2: Checking Spark Plug

      Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
   6. Install the ignition coil.
   7. Reconnect the injector connectors.

   NG:  Go to step  29

   OK: Go to next step 

9. CHECK CYLINDER COMPRESSION PRESSURE 
   1. Measure the cylinder compression pressure of the misfiring cylinder (See ON-VEHICLE INSPECTION ).

   NG: CHECK ENGINE TO DETERMINE CAUSE OF LOW COMPRESSION 

   OK: Go to next step 

10. INSPECT ECM TERMINAL OF MISFIRING CYLINDER (#10, #20, #30 AND/OR #40 VOLTAGE) 
    1. Disconnect the ECM connector.
    2. Turn the ignition switch to ON.
    3. Measure the voltage according to the value(s) in the table below.

       Standard voltage 

       VOLTAGE SPECIFICATION
       
       

       Tester Connection	Switch Condition	Specified Condition
       C19-108 (#10) - C19-45 (E01)	Ignition switch ON	11 to 14 V
       C19-107 (#20) - C19-45 (E01)	Ignition switch ON	11 to 14 V
       C19-106 (#30) - C19-45 (E01)	Ignition switch ON	11 to 14 V
       C19-105 (#40) - C19-45 (E01)	Ignition switch ON	11 to 14 V

    4. Reconnect the ECM connector.
       Fig 3: Identifying ECM Connector Terminals

       Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

    NG:  GO TO FUEL INJECTOR CIRCUIT 

    OK: Go to next step 

11. CHECK FUEL INJECTOR OF MISFIRING CYLINDER 
    1. Check the injector injection (whether fuel volume is high or low, and whether injection pattern is poor) (See INSPECTION ).

    NG: REPLACE FUEL INJECTOR  (See REMOVAL )

    OK: Go to next step 

12. CHECK VALVE CLEARANCE OF MISFIRING CYLINDER 
    1. Check the valve lash adjuster and valve rocker arm of misfiring cylinder (See INSPECTION ).

    NG: REPAIR OR REPLACE VALVE LASH ADJUSTER ASSEMBLY  (See DISASSEMBLY )

    OK: Go to next step 

13. CHECK AIR INDUCTION SYSTEM 
    1. Check the air induction system for vacuum leak (See ON-VEHICLE INSPECTION ).

       OK: 

       No leak from air induction system. 

    NG: REPAIR OR REPLACE AIR INDUCTION SYSTEM 

    OK: Go to next step 

14. CHECK VALVE TIMING  (See INSPECTION PROCEDURE  )

    NG: ADJUST VALVE TIMING  (See REASSEMBLY )

    OK: Go to next step 

15. CHECK FUEL PRESSURE 
    1. Check the fuel pressure (See ON-VEHICLE INSPECTION ).

    NG: REPAIR OR REPLACE FUEL PUMP, PRESSURE REGULATOR, FUEL PIPE LINE OR FILTER 

    OK: Go to next step 

16. READ VALUE USING TECHSTREAM (COOLANT TEMP)  (See INSPECTION PROCEDURE  )

    NG: REPLACE ENGINE COOLANT TEMPERATURE SENSOR  (See REMOVAL  )

    OK: Go to next step 

17. INSPECT MASS AIR FLOW METER  (See INSPECTION PROCEDURE  )

    NG: REPLACE MASS AIR FLOW METER  (See REMOVAL  )

    OK : REPLACE ECM  (See REMOVAL  )

18. CHECK AIR INDUCTION SYSTEM 
    1. Check the air induction system for vacuum leak (See ON-VEHICLE INSPECTION ).

       OK: 

       No leak from air induction system. 

    NG: REPAIR OR REPLACE AIR INDUCTION SYSTEM 

    OK: Go to next step 

19. CHECK VALVE TIMING  (See INSPECTION PROCEDURE  )

    NG: ADJUST VALVE TIMING  (See REASSEMBLY )

    OK: Go to next step 

20. CHECK FUEL PRESSURE 
    1. Check the fuel pressure (See ON-VEHICLE INSPECTION ).

    NG: REPAIR OR REPLACE FUEL PUMP, PRESSURE REGULATOR, FUEL PIPE LINE OR FILTER 

    OK: Go to next step 

21. READ VALUE USING TECHSTREAM (COOLANT TEMP)  (See INSPECTION PROCEDURE  )

    NG: REPLACE ENGINE COOLANT TEMPERATURE SENSOR  (See REMOVAL  )

    OK: Go to next step 

22. INSPECT MASS AIR FLOW METER  (See INSPECTION PROCEDURE  )

    NG: REPLACE MASS AIR FLOW METER  (See REMOVAL  )

    OK: Go to next step 

23. INSPECT SPARK PLUG 
    1. Remove the ignition coil and the spark plug of the misfiring cylinder.
    2. Measure the spark plug electrode gap.

       Standard gap: 

       1.0 to 1.1 mm (0.039 to 0.043 in.) 

    3. Check the electrode for carbon deposits.

       Recommended spark plug: 

       RECOMMENDED SPARK PLUG REFERENCE
       
       

       Manufacturer	Product
       DENSO	SC20HR11

       NOTE: If the electrode gap is larger than standard, replace the spark plug. Do not adjust the electrode gap.
       Fig 4: Identifying Spark Plug Electrode Gap

       Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    4. Reinstall the ignition coil.

    NG: REPLACE SPARK PLUG  (See REMOVAL )

    OK: Go to next step 

24. CHECK FOR SPARKS AND IGNITION 
    1. Disconnect the injector connectors to prevent the engine from starting.
       CAUTION: Always disconnect all injector connectors.
    2. Remove the ignition coil from the cylinder head.
    3. Install the spark plug onto the ignition coil.
    4. Attach the spark plug assembly to the cylinder head.
    5. Crank the engine for less than 2 seconds and check the spark.
       NOTE: Do not crank the engine for more than 2 seconds.

       OK: 

       Sparks jump across electrode gap. 

       Fig 5: Checking Spark Plug

       Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    6. Install the ignition coil.
    7. Reconnect the injector connectors.

    NG:  Go to step  29

    OK: Go to next step 

25. CHECK CYLINDER COMPRESSION PRESSURE 
    1. Measure the cylinder compression pressure of the misfiring cylinder (See ON-VEHICLE INSPECTION ).

    NG: CHECK ENGINE TO DETERMINE CAUSE OF LOW COMPRESSION 

    OK: Go to next step 

26. INSPECT ECM TERMINAL OF MISFIRING CYLINDER (#10, #20, #30 AND/OR #40 VOLTAGE) 
    1. Disconnect the ECM connector.
    2. Turn the ignition switch to ON.
    3. Measure the voltage according to the value(s) in the table below.

       Standard voltage 

       VOLTAGE SPECIFICATION
       
       

       Tester Connection	Switch Condition	Specified Condition
       C19-108 (#10) - C19-45 (E01)	Ignition switch ON	11 to 14 V
       C19-107 (#20) - C19-45 (E01)	Ignition switch ON	11 to 14 V
       C19-106 (#30) - C19-45 (E01)	Ignition switch ON	11 to 14 V
       C19-105 (#40) - C19-45 (E01)	Ignition switch ON	11 to 14 V

    4. Reconnect the ECM connector.
       Fig 6: Identifying ECM Connector Terminals

       Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

    NG:  GO TO FUEL INJECTOR CIRCUIT 

    OK: Go to next step 

27. CHECK FUEL INJECTOR OF MISFIRING CYLINDER 
    1. Check the injector injection (whether fuel volume is high or low, and whether injection pattern is poor) (See INSPECTION ).

    NG: REPLACE FUEL INJECTOR  (See REMOVAL )

    OK: Go to next step 

28. CHECK VALVE CLEARANCE OF MISFIRING CYLINDER 
    1. Check the valve lash adjuster and valve rocker arm of misfiring cylinder (See INSPECTION ).

    NG: REPAIR OR REPLACE VALVE LASH ADJUSTER ASSEMBLY  (See DISASSEMBLY )

    OK : REPLACE ECM  (See REMOVAL  )

29. CHANGE TO NORMAL SPARK PLUG AND CHECK SPARK OF MISFIRING CYLINDER 
    1. Change the installed spark plug to a spark plug that functions normally.
    2. Perform a spark test.
       CAUTION: Always disconnect all injector connectors.
       NOTE: Do not crank the engine for more than 2 seconds.
       1. Install the spark plug into the ignition coil and connect the ignition coil connector.
       2. Disconnect the injector connector.
       3. Ground the spark plug.
       4. Check if sparks occur while the engine is being cranked.

          OK: 

          Sparks jump across electrode gap. 

    NG: Go to step 30 

    OK : REPLACE SPARK PLUG  (See REMOVAL )

30. CHANGE TO NORMAL IGNITION COIL AND CHECK SPARK OF MISFIRING CYLINDER 
    1. Change the ignition coil to a ignition coil that functions normally.
    2. Perform a spark test.
       CAUTION: Always disconnect all injector connectors.
       NOTE: Do not crank the engine for more than 2 seconds.
       1. Install the spark plug into the ignition coil and connect the ignition coil connector.
       2. Disconnect the injector connector.
       3. Ground the spark plug.
       4. Check if sparks occur while the engine is being cranked.

          OK: 

          Sparks jump across electrode gap. 

    NG: REPLACE ECM  (See REMOVAL  )

    OK : REPLACE IGNITION COIL  (See REMOVAL )