Inspection Procedure

HINT:

• If any DTCs other than the misfire DTCs are output, troubleshoot those DTCs first.
• Read freeze frame data using the intelligent tester. 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 freeze frame data.
• If the misfire still cannot be reproduced even though the conditions stored in the freeze frame data have been duplicated, one of the following factors is considered to be a possible cause of the problem:
  1. The fuel tank is almost empty.
  2. Improper fuel is used.
  3. The spark plugs have been contaminated.
  4. The problem is complex.
• After finishing repairs, check the misfire counts of the cylinders (CYL #1, #2, #3 and #4).
• Be sure to confirm that no misfiring cylinder DTCs are set again by conducting the confirmation driving pattern, after repairs.
• For 6 and 8 cylinder engines, the ECM intentionally does not set the specific misfiring cylinder DTCs at high engine RPM. If misfires occur only in high engine RPM areas, only DTC P0300 is set. In the event of DTC P0300 being present, perform the following operations:
  1. Clear the DTC (See DTC CHECK / CLEAR  ).
  2. Start the engine and conduct the confirmation driving pattern.
  3. Read the misfiring rates of each cylinder or DTC(s) using the tester.
  4. Repair the cylinder(s) that has a high misfiring rate or is indicated by the DTC.
  5. After finishing repairs, conduct the confirmation driving pattern again, in order to verify that DTC P0300 is not set.
• 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 misfires have occurred only while warming up the engine.

1. CHECK ANY OTHER DTCS OUTPUT (IN ADDITION TO MISFIRE DTCS) 
   1. Connect the intelligent tester to the DLC3.
   2. Turn the ignition switch to the ON position.
   3. Turn the tester on.
   4. Enter the following menus: DIAGNOSIS / ENHANCED OBD II / DTC INFO / CURRENT CODES.
   5. Read the DTCs.

      Result 

      DTC RESULT REFERENCE
      
      

      Display (DTC Output)	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  

   A: GO TO NEXT STEP 

2. READ VALUE USING INTELLIGENT TESTER (MISFIRE RPM AND MISFIRE LOAD) 
   NOTE: If the intelligent tester is not available, proceed to the next step.
   1. Connect the intelligent tester to the DLC3.
   2. Turn the ignition switch to the ON position and turn the tester on.
   3. Enter the following menus: DIAGNOSIS / ENHANCED OBD II / DATA LIST / MISFIRE / MISFIRE RPM and MISFIRE LOAD.
   4. Read and note the MISFIRE RPM and MISFIRE LOAD (engine load) values.

      HINT:

      The MISFIRE RPM and MISFIRE LOAD indicate the vehicle conditions under which the misfire occurred.

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 AND #4) 
   1. Connect the intelligent tester to the DLC3.
   2. Turn the ignition switch to the ON position.
   3. Turn the tester on.
   4. Clear the DTCs (See DTC CHECK / CLEAR  ) (Procedure "A").
   5. Enter the following menus: DIAGNOSIS / ENHANCED OBD II / DATA LIST / ALL / CYL #1, #2, #3 and #4 (Procedure "B").
   6. Allow the engine to idle (Procedure "C").
   7. Read each value of CYL #1 to #4 displayed on the tester (Procedure "D").

      If no misfire counts occur in any cylinders, perform the following operations:

      1. Shift the gear selector lever to the D position.
      2. Repeat Procedure "A" and "B" above.
      3. Check the CYL #1 to #4.
      4. If misfire counts are still not displayed, repeat Procedure "D" and then check the misfire counts again.
   8. Drive the vehicle with the MISFIRE RPM and MISFIRE LOAD noted in step  2.
   9. Read the CYL #1 to #4 or DTCs displayed on the tester.

      Result 

      RESULT REFERENCE
      
      

      Misfire Count	Proceed to
      1 or 2 cylinders have misfire counts	A
      3 cylinders or more have misfire counts	B

   B: Go to step   13 

   A: GO TO NEXT STEP 

5. CHECK SPARK PLUG 
   1. Remove the No. 2 cylinder head cover.
   2. Remove the ignition coil and the spark plug of the misfiring cylinder.
   3. Measure the spark plug electrode gap.

      Standard gap: 

      1.0 to 1.3 mm (0.039 to 0.051 in.) 

   4. Check the electrode for carbon deposits.

      Recommended spark plug 

      SPARK PLUG SPECIFICATION
      
      

      Manufacturer	Product
      DENSO	SK20R11
      NGK	IFR6A11

      Fig 1: Measuring Spark Plug Electrode Gap

      Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
      NOTE: If the electrode gap is larger than standard, replace the spark plug. Do not adjust the electrode gap.

   NG: REPLACE SPARK PLUG 

   OK: GO TO NEXT STEP 

6. CHECK SPARK AND IGNITION 
   1. Disconnect the injector connectors in order to prevent the engine from starting.
   2. Install the spark plug to the ignition coil.
   3. Attach the spark plug assembly to the cylinder head cover.
   4. Crank the engine for less than 2 seconds and check the spark.

      OK: 

      Sparks jump across electrode gap 

   NG: Go to step   8 

   Fig 2: Checking Spark

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

   OK: GO TO NEXT STEP 

7. CHECK CYLINDER COMPRESSION PRESSURE OF MISFIRING CYLINDER 
   1. Measure the cylinder compression pressure of the misfiring cylinder.

   OK: Go to step   9 

   NG: REPAIR OR REPLACE MALFUNCTION PARTS 

8. CHANGE 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 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 connectors.
      3. Ground the spark plug.
      4. Check if sparks occur while the engine is being cranked.

         OK: 

         Sparks jump across electrode gap. 

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

   OK: REPLACE SPARK PLUG 

9. INSPECT ECM TERMINAL OF MISFIRING CYLINDER (#1, #2, #3 AND/OR #4 VOLTAGE) 
   1. Turn the ignition switch to the ON position.
   2. Measure the voltage according to the value(s) in the table below.

      Standard voltage 

      ECM TERMINAL OF MISFIRING CYLINDER TESTER CONNECTION AND SPECIFIED CONDITION
      
      

      Tester Connection	Specified Condition
      #1 (E7-6) - E01 (E8-7)	9 to 14 V
      #2 (E7-S) - E01 (E8-7)	9 to 14 V
      #3 (E7-2) - E01 (E8-7)	9 to 14 V
      #4 (E7-1) - E01 (E8-7)	9 to 14 V

   OK: Go to step   11 

   Fig 3: Identifying ECM Connector Terminals

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

   NG: GO TO NEXT STEP 

10. CHECK WIRE HARNESS (INJECTOR - ECM) 
    1. Disconnect the injector connector (of the misfiring cylinder).
    2. Disconnect the E7 ECM connector.
    3. Turn the ignition switch to the ON position.
    4. Measure the resistance and voltage according to the value(s) in the table below.
       Fig 4: Disconnecting E7 ECM Connector

       Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

       Standard: 

       Cylinder No. 1 

       WIRE HARNESS TESTER CONNECTION AND SPECIFIED CONDITION (CYLINDER NO. 1)
       
       

       Tester Connection	Specified Condition
       F1-1 - Ground	11 to 14 V
       F1-2 - Ground	10 kΩ or higher
       F1-2-#1(E7-6)	Below 1 Ω

       Cylinder No. 2 

       WIRE HARNESS TESTER CONNECTION AND SPECIFIED CONDITION (CYLINDER NO. 2)
       
       

       Tester Connection	Specified Condition
       F2-1 -Ground	11 to 14 V
       F2-2 - Ground	10 kΩ or higher
       F2-2-#2(E7-5)	Below 1 Ω

       Cylinder No. 3 

       WIRE HARNESS TESTER CONNECTION AND SPECIFIED CONDITION (CYLINDER NO.3)
       
       

       Tester Connection	Specified Condition
       F3-1 -Ground	11 to 14 V
       F3-2 - Ground	10 kΩ or higher
       F3-2-#3(E7-2)	Below 1 Ω

       Cylinder No. 4 

       WIRE HARNESS TESTER CONNECTION AND SPECIFIED CONDITION (CYLINDER NO. 4)
       
       

       Tester Connection	Specified Condition
       F4-1 - Ground	11 to 14 V
       F4-2 - Ground	10 kΩ or higher
       F4-2-#4(E7-1)	Below 1 Ω

    NG: REPAIR OR REPLACE HARNESS OR CONNECTOR 

    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).

    NG: REPLACE FUEL INJECTOR ASSEMBLY 

    OK: GO TO NEXT STEP 

12. CHECK VALVE CLEARANCE OF MISFIRING CYLINDER 

    NG: ADJUST VALVE CLEARANCE 

    OK: GO TO NEXT STEP 

13. CHECK AIR INDUCTION SYSTEM 
    1. Check the air induction system for vacuum leakage.

       OK: 

       No leakage from air induction system. 

    NG: REPAIR OR REPLACE AIR INDUCTION SYSTEM 

    OK: GO TO NEXT STEP 

14. CHECK VALVE TIMING 
    1. Remove the cylinder head cover (See DISASSEMBLY ).
    2. Turn the crankshaft pulley until its groove and the timing mark "0" of the timing chain cover are aligned.
    3. Check that each timing mark of the camshaft timing gears is aligned with its corresponding timing mark located on the No.1 and No.2 bearing caps as shown in the illustration.

       If not, turn the crankshaft by 1 revolution (360°) to align the timing marks as above.

       OK: 

       The timing marks of the camshaft timing gears are aligned with the timing marks located on the No. 1 and No. 2 bearing caps. 

    4. Reinstall the cylinder head cover (See INSTALLATION ).

    NG: ADJUST VALVE TIMING 

    Fig 5: Identifying Timing Mark Of Camshaft Timing Gears

    Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

    OK: GO TO NEXT STEP 

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

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

    OK: GO TO NEXT STEP 

16. READ VALUE USING INTELLIGENT TESTER (COOLANT TEMP) 
    1. Connect the intelligent tester to the DLC3.
    2. Turn the ignition switch to the ON position.
    3. Turn the tester on.
    4. On the tester, select the following menu items: DIAGNOSIS / ENHANCED OBD II / DATA LIST / ALL / COOLANT TEMP.
    5. Read the COOLANT TEMP twice, when the engine is both cold and warmed up.

       Standard temperature: 

       With cold engine: 

       Same as ambient air temperature 

       With warm engine: 

       75 to 95°C (167 to 203°F) 

    NG: REPLACE ENGINE COOLANT TEMPERATURE SENSOR 

    OK: GO TO NEXT STEP 

17. READ VALVE USING INTELLIGENT TESTER 
    1. Connect the intelligent tester to the DLC3.
    2. Turn the ignition switch to the ON position.
    3. Turn the tester on.
    4. Enter the following menu items: DIAGNOSIS / ENHANCED OBD II / DATA LIST / ALL / MAF and COOLANT TEMP.
    5. Allow the engine to idle until the COOLANT TEMP reaches 75°C (167°F) or more.
    6. Read the MAF with the engine in an idling condition and at an engine speed of 2,500 rpm.

       Standard: 

       MAF while engine idling: 

       Between 0.54 gm/s and 4.33 gm/s (shift position: N; A/C: OFF) 

       MAF at engine speed of 2,500 rpm: 

       Between 0.58 gm/s and 4.67 gm/s (shift position: N; A/C: OFF) 

    NG: REPLACE MASS AIR FLOW METER 

    OK: CHECK FOR INTERMITTENT PROBLEMS