Inspection Procedure

HINT:

• If any DTCs other than misfire DTCs are output, troubleshoot those DTCs first.
• Read freeze frame data using the Techstream. The ECM records vehicle and driving condition information as freeze frame data the moment a DTC is stored. When troubleshooting, freeze frame data can be helpful in determining whether the vehicle was running or stopped, whether the engine was warmed up or not, whether the air fuel ratio was lean or rich, as well as other data recorded at the time of a malfunction.
• 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 Count to Cylinder #4 Misfire Count).
• 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 occurred while warming up the engine.
• An extremely imbalanced drive wheel which causes body vibration may cause misfire DTCs to be detected.

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

      HINT:

      Write down indicated DTCs.

   Result 

   DTC 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 the Techstream to the DLC3.
   2. Turn the ignition switch to ON.
   3. Turn the Techstream on.
   4. Enter the following menus: 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 occurs.

3. CHECK PCV HOSE CONNECTIONS 
   1. Check PCV hose.

   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 (CATALYST OT MF F/C) 
   1. Connect the Techstream to the DLC3.
   2. Turn the ignition switch to ON.
   3. Turn the Techstream on.
   4. Enter the following menus: Powertrain / Engine and ECT / Data List / Catalyst OT MF F/C.
   5. Read the value displayed on the Techstream.

   Result 

   DTC 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 CATALYST OT MISFIRE PREVENT F/C) 
   1. Connect the Techstream to the DLC3.
   2. Turn the ignition switch to ON.
   3. Turn the Techstream on.
   4. Enter the following menus: 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 at 3000 rpm or less.
6. READ VALUE USING TECHSTREAM (CYLINDER #1, #2, #3 AND #4) 
   1. Enter the following menus: Powertrain / Engine and ECT / Data List / Misfire / Cylinder #1 Misfire Count, #2, #3 and #4.
   2. Start the engine and allow the engine to idle.
   3. Read each value for Cylinder #1 Misfire Count to #4 displayed on the Techstream. 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 Count to #4 or DTCs displayed on the Techstream.

   Result 

   DTC 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 record of the engine coolant temperature is below 75°C (167°F), it may only be possible to detect the misfire when the engine is cold.
   • If the freeze frame data 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 (0.0394 to 0.0433 in.) 

   3. Check the electrode for carbon deposits.
      Fig 1: Identifying Spark Plug Electrode Gap

      Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

      Recommended Spark Plug: 

      SPARK PLUG SPECIFICATION
      
      

      Manufacturer	Product
      DENSO	SK20R11
      NGK	IFR6A11

      NOTE: If the electrode gap is not as specified, replace the spark plug. Do not adjust the electrode gap.
   4. Reinstall the ignition coil.

   NG: REPLACE SPARK PLUG  (See IGNITION COIL AND SPARK PLUG )

   OK: Go to next step 

8. CHECK FOR SPARK 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. Touch the spark plug assembly to the cylinder head.
   5. Crank the engine for less than 2 seconds and check for spark.
      Fig 2: Disconnecting Injector Connectors

      Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
      NOTE: Do not crank the engine for more than 2 seconds.

      OK: 

      Sparks jump across electrode gap. 

   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 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
       B31-108 (#10) - B31-45 (E01)	Ignition switch ON	11 to 14 V
       B31-107 (#20) - B31-45 (E01)	Ignition switch ON	11 to 14 V
       B31-106 (#30) - B31-45 (E01)	Ignition switch ON	11 to 14 V
       B31-10 5(#40) - B31-45 (E01)	Ignition switch ON	11 to 14 V

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

    Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

    NG: GO TO FUEL INJECTOR CIRCUIT  (See 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 FUEL INJECTOR )

    OK: Go to next step 

12. CHECK VALVE CLEARANCE OF MISFIRING CYLINDER 
    1. Check the valve clearance (See VALVE CLEARANCE ).

    NG: ADJUST VALVE CLEARANCE  (See VALVE CLEARANCE )

    OK: Go to next step 

13. CHECK INTAKE SYSTEM 
    1. Check the intake system for vacuum leaks (See INTAKE SYSTEM ).

    OK: 

    No leaks in intake system. 

    NG: REPAIR OR REPLACE INTAKE 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 ENGINE COOLANT TEMPERATURE SENSOR )

    OK: Go to next step 

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

    NG: REPLACE MASS AIR FLOW METER  (See MASS AIR FLOW METER )

    OK: REPLACE ECM  (See ECM )

18. CHECK INTAKE SYSTEM 
    1. Check the intake system for vacuum leaks (See INTAKE SYSTEM ).

    OK: 

    No leaks in intake system. 

    NG: REPAIR OR REPLACE INTAKE 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 ENGINE COOLANT TEMPERATURE SENSOR )

    OK: Go to next step 

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

    NG: REPLACE MASS AIR FLOW METER  (See MASS AIR FLOW METER )

    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 (0.0394 to 0.0433 in.) 

    3. Check the electrode for carbon deposits.

       Recommended Spark Plug: 

       SPARK PLUG SPECIFICATION
       
       

       Manufacturer	Product
       DENSO	SK20R11
       NGK	IFR6A11

       Fig 4: Identifying Spark Plug Electrode Gap

       Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
       NOTE: If the electrode gap is not as specified, replace the spark plug. Do not adjust the electrode gap.
    4. Reinstall the ignition coil.

    NG: REPLACE SPARK PLUG  (See IGNITION COIL AND SPARK PLUG )

    OK: Go to next step 

24. CHECK FOR SPARK 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. Touch the spark plug tip to the cylinder head.
    5. Crank the engine for less than 2 seconds and check for spark.
       Fig 5: Disconnecting Injector Connectors

       Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
       NOTE: Do not crank the engine for more than 2 seconds.

       OK: 

       Sparks jump across electrode gap. 

    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 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
       B31-108 (#10) - B31-45 (E01)	Ignition switch ON	11 to 14 V
       B31-107 (#20) - B31-45 (E01)	Ignition switch ON	11 to 14 V
       B31-106 (#30) - B31-45 (E01)	Ignition switch ON	11 to 14 V
       B31-105 (#40) - B31-45 (E01)	Ignition switch ON	11 to 14 V

       Fig 6: Identifying ECM Connector Terminal

       Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    4. Reconnect the ECM connector.

    NG: GO TO FUEL INJECTOR CIRCUIT  (See 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 FUEL INJECTOR )

    OK: Go to next step 

28. CHECK VALVE CLEARANCE OF MISFIRING CYLINDER 
    1. Check the valve clearance (See VALVE CLEARANCE ).

    NG: ADJUST VALVE CLEARANCE  (See VALVE CLEARANCE )

    OK: REPLACE ECM  (See ECM )

29. CHANGE TO KNOWN GOOD SPARK PLUG AND CHECK SPARK OF MISFIRING CYLINDER 
    1. Change the installed spark plug to a known good spark plug.
    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 connectors.
       3. Ground the spark plug.
       4. Check if spark occurs while the engine is being cranked.

          OK: 

          Sparks jump across electrode gap. 

    NG: Go to step 30 

    OK: REPLACE SPARK PLUG  (See IGNITION COIL AND SPARK PLUG )

30. CHANGE TO KNOWN GOOD IGNITION COIL AND CHECK SPARK OF MISFIRING CYLINDER 
    1. Change the ignition coil to a known good ignition coil.
    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 ECM )

    OK: REPLACE IGNITION COIL  (See IGNITION COIL AND SPARK PLUG )