Inspection Procedure

HINT:

• If any DTCs other than the misfire DTCs are output, troubleshoot those DTCs first.
• Read freeze frame data using the hand-held tester or the OBD II scan tool. Freeze frame data record the engine conditions 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 freeze frame data.
• 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 low full.
  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.

  P0300 being present, perform the following open 

  1. Clear the DTC (see DIAGNOSTIC TROUBLE CODES 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 or scan tool.
  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 a hand-held tester or OBD II scan tool to the DLC3.
   2. Turn the ignition switch to ON.
   3. Turn the tester or scan tool ON.
   4. On the tester, select the following menu items: DIAGNOSIS / ENHANCED OBD II / DTC INFO / CURRENT CODES.
   5. Read DTCs.
   6. If using an OBD II scan tool, refer to the instruction manual .

      Result: 

      DTC OUTPUT RESULT
      
      

      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.

   1. B: GO TO  DIAGNOSTIC TROUBLE CODE CHART  
   2. A: GO TO NEXT STEP 
2. READ VALUE USING HAND-HELD TESTER OR OBD II SCAN TOOL (MISFIRE RPM AND MISFIRE LOAD) 
   NOTE: If a hand-held tester is not available, proceed to step 3.
   1. Connect the hand-held tester to the DLC3.
   2. Turn the ignition switch to ON and turn the tester ON.
   3. Select the following menu items: 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.

   NEXT: GO TO NEXT STEP 

3. CHECK PCV HOSE CONNECTIONS 

   OK: PCV hose is connected correctly and is not damaged. 

   1. NG: REPAIR OR REPLACE PCV HOSE 
   2. OK: GO TO NEXT STEP 
4. READ VALUE USING HAND-HELD TESTER OR OBD II SCAN TOOL (NUMBER OF MISFIRE CYLINDER) 
   1. Connect the hand-held tester or OBD II scan tool to the DLC3.
   2. Turn the ignition switch to ON.
   3. Turn the tester or scan tool ON.
   4. Clear DTCs (see DIAGNOSTIC TROUBLE CODES CHECK/CLEAR ).
   5. If using an OBD II scan tool, go to step 5.
   6. On the tester, select the following menu items: DIAGNOSIS / ENHANCED OBD II / DATA LIST / ALL /CYL#1,#2, #3 and #4.
   7. Allow the engine to idle.
   8. Read each value of CYL #1 to #4 displayed on the tester. If no misfire counts occur in any cylinders, perform the following operations:
      1. Shift the gear selector lever to the D position.
      2. Repeat steps (d) and (f) above.
      3. Check the CYL #1 to #4.
      4. If misfire counts are still not displayed, repeat (g) and then check the misfire counts again.
   9. Drive the vehicle with the MISFIRE RPM and MISFIRE LOAD noted in step 2.
   10. Read the CYL #1 to #4 or DTCs displayed on the tester.

       Result: 

       MISFIRE COUNT RESULT
       
       

       Misfire Count	Proceed To
       One or two cylinders have misfire counts	A
       Three cylinders or more have misfire counts	B

   1. B: Go to step   13 
   2. A: GO TO NEXT STEP 
5. CHECK SPARK PLUG 
   1. Remove cylinder head cover No. 2.
   2. Remove the ignition coil and the spark plug of the misfiring cylinder.
   3. Measure the spark plug electrode gap.

      Standard: Between 1.0 mm and 1.3 mm (0.039 in. and 0.051 in.) 

   4. Check the electrode for carbon deposits.

      Recommended spark plug: 

      RECOMMENDED SPARK PLUG
      
      

      Manufacturers	Products
      DENSO	SK20R11
      NGK	IFR6A11

      Fig 1: Checking 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.
   1. NG: REPLACE SPARK PLUG 
   2. OK: GO TO NEXT STEP 
6. CHECK FOR SPARKS 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 

   5. Reconnect the injector connectors.
      Fig 2: Checking Sparks And Ignition

      Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
   1. NG: Go to step   8 
   2. OK: GO TO NEXT STEP 
7. CHECK CYLINDER COMPRESSION PRESSURE OF MISFIRING CYLINDER (See  ENGINE ASSEMBLY (2ZZ-GE)  ) 
   1. Measure the cylinder compression pressure of the misfiring cylinder.
   1. OK: Go to step   9 
   2. NG: GO TO NEXT STEP 

      REPAIR OR REPLACE 

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

         OK: Sparks jump across electrode gap. 

   1. NG: REPLACE IGNITION COIL ASSY 
   2. OK: GO TO NEXT STEP 

      REPLACE SPARK PLUG 

9. INSPECT ECM TERMINAL OF MISFIRING CYLINDER (#10, #20, #30 AND/OR #40 VOLTAGE) 
   1. Turn the ignition switch to ON.
   2. Measure the voltage between the terminals of the E3 ECM connector.

      Standard: 

      ECM TERMINAL VOLTAGE
      
      

      Tester Connections	Specified Conditions
      #10 (E3-1)-E01 (E3-7)	Between 9 V and 14 V
      #20 (E3-2)-E01 (E3-7)	Between 9 V and 14 V
      #30 (E3-3)-E01 (E3-7)	Between 9 V and 14 V
      #40 (E3-4)-E01 (E3-7)	Between 9 V and 14 V

      Fig 3: Inspecting ECM Terminal Of Misfiring Cylinder (#10, #20, #30 And/Or #40 Voltage)

      Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
   1. OK: Go to step   11 
   2. NG: GO TO NEXT STEP 
10. CHECK HARNESS AND CONNECTOR OF MISFIRING CYLINDER (INJECTOR ECM) 
    1. Disconnect the injector connector (of the misfiring cylinder).
    2. Disconnect the E3 ECM connector.
    3. Turn the ignition switch to ON.
    4. Measure the resistance and voltage between the injector and the ECM connector terminals.
       Fig 4: Identifying Terminals Of Injector Connector

       Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

       Standard (Cylinder No. 1): 

       Cylinder No. 1 TESTER CONNECTION SPECIFIED CONDITIONS
       
       

       Tester Connections	Specified Conditions
       I6-1-Ground	Between 11 V and 14 V
       I6-2-Ground	10kΩ or higher
       I6-2-#10 (E3-1)	Below 1 Ω

       Standard (Cylinder No. 2): 

       CYLINDER NO. 2 TESTER CONNECTION SPECIFIED CONDITIONS
       
       

       Tester Connections	Specified Conditions
       I7-1-Ground	Between 11 V and 14 V
       I7-2- Ground	10 kΩ or higher
       I7-2-#20 (E3-2)	Below 1 Ω

       Standard (Cylinder No. 3): 

       CYLINDER NO. 3 TESTER CONNECTION SPECIFIED CONDITIONS
       
       

       Tester Connections	Specified Conditions
       I8-1 -Ground	Between 11 V and 14 V
       I8-2-Ground	10 kΩ or higher
       I8-2-#30 (E3-3)	Below 1 Ω

       Fig 5: Disconnecting E3 ECM Connector

       Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

       Standard (Cylinder No. 4): 

       CYLINDER NO. 4 TESTER CONNECTION SPECIFIED CONDITIONS
       
       

       Tester Connections	Specified Conditions
       I9-1 -Ground	Between 11 V and 14 V
       I9-2- Ground	10 kΩ or higher
       I9-2-#40 (E3-4)	Below 1 Ω

    5. Reconnect the injector connector.
    6. Reconnect the ECM connector.
    1. NG: REPAIR OR REPLACE HARNESS OR CONNECTOR 
    2. OK: GO TO NEXT STEP 
11. CHECK FUEL INJECTOR OF MISFIRING CYLINDER (See  INSPECTION  ) 
    1. Check the injector injection (whether fuel volume is high or low, and whether injection pattern is poor.)
    1. NG: REPLACE FUEL INJECTOR ASSY (See  REPLACEMENT  ) 
    2. OK: GO TO NEXT STEP 
12. CHECK VALVE CLEARANCE OF MISFIRING CYLINDER (See  VALVE CLEARANCE (2ZZ-GE)  ) 
    1. NG: ADJUST VALVE CLEARANCE (See  VALVE CLEARANCE (1ZZ-FE)  ) 
    2. 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. 

    1. NG: REPAIR OR REPLACE AIR INDUCTION SYSTEM 
    2. OK: GO TO NEXT STEP 
14. CHECK VALVE TIMING 
    1. Remove the cylinder head cover (see VALVE CLEARANCE (2ZZ-GE) ).
    2. Turn the crankshaft pulley, then align its groove with the timing mark "0" on the timing chain cover.
    3. Check that the point marks on the camshaft timing gears are as shown in the illustration.

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

       OK: Point marks on camshaft timing gears are as shown in the illustration. 

    4. Reinstall the cylinder head cover (see VALVE CLEARANCE (2ZZ-GE) ).
       Fig 6: Checking Valve Timing

       Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    1. NG: ADJUST VALVE TIMING (See  VALVE CLEARANCE (2ZZ-GE)  ) 
    2. OK: GO TO NEXT STEP 
15. CHECK FUEL PRESSURE (See  ON-VEHICLE INSPECTION  ) 
    1. Check the fuel pressure.
    1. NG: CHECK AND REPLACE FUEL PUMP, PRESSURE REGULATOR, FUEL PIPE LINE AND FILTER 
    2. OK: GO TO NEXT STEP 
16. READ VALUE USING HAND-HELD TESTER OR OBD II SCAN TOOL (COOLANT TEMPERATURE) 
    1. Connect the hand-held tester or OBD II scan tool to the DLC3.
    2. Turn the ignition switch to ON.
    3. Turn the tester or scan tool 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.
    6. If using an OBD II scan tool, refer to the instruction manual .

       Standard: 

       With cold engine: Same as ambient air temperature. 

       With warm engine: Between 75°C and 95°C (167°F and 203& 

    1. NG: REPLACE ENGINE COOLANT TEMPERATURE SENSOR 
    2. OK: GO TO NEXT STEP 
17. READ VALUE USING HAND-HELD TESTER OR OBD II SCAN TOOL (MASS AIR FLOW RATE) 
    1. Connect the hand-held tester or OBD II scan tool to the DLC3.
    2. Turn the ignition switch to ON.
    3. Turn the tester or scan tool ON.
    4. On the tester, select 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.
    7. If using an OBD II scan tool, refer to the instruction manual .

       Standard: 

       MAF while engine idling: Between 1.5 gm/s and 5.0 gm/s (A/C 

       of 2,500 rpm: Between 5.0 gm/s and 15.0 gm/s (A/C: OFF). 

    1. NG: REPLACE MASS AIR FLOW METER 
    2. OK: GO TO NEXT STEP 

       CHECK FOR INTERMITTENT PROBLEMS