Inspection Procedure

HINT:

• If DTCs besides misfire DTCs are memorized simultaneously, troubleshoot the non-misfire DTCs first.
• If the misfire does not occur when the vehicle is brought to the workshop, the misfire can be confirmed by reproducing the condition of the freeze frame data. Also, after finishing the repair, confirm that there is no misfire (See confirmation driving pattern).
• On 6 or 8 cylinder engines, misfiring cylinder identification is disabled at high engine speed and only a general misfire fault code P0300 is stored instead of a cylinder specific misfire fault code (P0301 to P0308).

  If the misfire starts in a high engine speed area or the misfire occurs only in a high engine speed area, only code P0300 may be stored.

  When only a general misfire fault code like P0300 is stored:

• Erase the general misfire fault code using the hand-held tester
• Start the engine and drive the confirmation pattern.
• Read the value of the misfire ratio for each cylinder. Or read the DTC.
• Repair the cylinder that has a high misfire ratio. Or repair the cylinder indicated by the DTC.
• After finishing repairs, drive the confirmation pattern again and confirm that no misfire occurs.
• When either of SHORT FT #1, LONG FT #1, SHORT FT #2 or LONG FT #2 in the freeze frame data is over the range of +/-20 %, there is a possibility that the air-fuel ratio is becoming RICH (-20 % or less) or LEAN (+20 % or more).
• When COOLANT TEMP in the freeze frame data is less than 80°C (176°F), there is a possibility of misfire only during engine warm-up.
• If the misfire cannot be reproduced, the following reasons may apply: 1) the vehicle has low fuel, 2) improper fuel is being used, or 3) the ignition plug is contaminated.
• Be sure to check the value on the misfire counter after the repair.

1. Are there any other codes (besides DTC P0300, P0301, P0302, P0303, P0304 P0305, P0306, P0307 or P0308) being output? 

   PREPARATION: 

   1. Connect the hand-held tester to the DLC3.
   2. Turn the ignition switch ON and push the hand-held tester main switch ON.
   3. When using hand-held tester, enter the following menu: DIAGNOSIS / ENHANCED OBD II / DTC INFO / CURRENT CODES.

   CHECK: 

   Read the DTCs using hand-held tester.

   RESULT: 

   DTC OUTPUT DESCRIPTION
   
   

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

   HINT:

   If any other codes besides "P0300, P0301, P0302, P0303, P0304, P0305, P0306, P0307 or P0308" are output, perform the troubleshooting for those DTCs.

   1. B: Go to relevant  DIAGNOSTIC TROUBLE CODE CHART  
   2. A: Go to next step 
2. Check wire harness, connector and vacuum hose in engine room. 

   CHECK: 

   1. Check the connection conditions of the wire harness and connector.
   2. Check for the disconnection, piping and brake of the vacuum hose.
   1. NG: Repair or replace, then confirm that there is no misfire (See confirmation driving pattern). 
   2. OK: Go to next step 
3. Check connection of PCV piping. 

   OK: 

   PCV hose is connected correctly and is not damaged. 

   1. NG: Repair or replace PCV piping. 
   2. OK: Go to next step 
4. Connect hand-held tester, and read the number of misfire. 

   PREPARATION: 

   1. Connect the hand-held tester to the DLC3.
   2. Turn the ignition switch ON and push the hand-held tester main switch ON.
   3. Start the engine.
   4. When using hand-held tester, enter the following menu: DIAGNOSIS / ENHANCED OBD II / DATA LIST / ALL / CYL#1 to CYL#8.

   CHECK: 

   Read the number of misfire on the hand-held tester.

   HINT:

   When a misfire is not reproduced, be sure to branch below based on the stored DTC.

   RESULT: 

   HIGH MISFIRE RATE CYLINDER DESCRIPTION
   
   

   High Misfire Rate Cylinder	Proceed to
   1 or 2 cylinders	A
   More than 3 cylinders	B

   1. B: Go to step   15 . 
   2. A: Go to next step 
5. Check spark plug and spark of misfiring cylinder. 

   PREPARATION: 

   1. Remove the ignition coil assembly.
   2. Remove the spark plug.

   CHECK: 

   1. Check the electrode for carbon deposits.
   2. Check the spark plug type (See IGNITION SYSTEM ).
   3. Check electrode gap.

   OK: 

   No large carbon deposit present. 

   Not wet with gasoline or oil. 

   Electrode gap: 0.8 mm (0.031 in.) 

   NOTE: If adjusting the gap of a new spark plug, bend only "the base / ground" electrode. Do not touch the tip. Never attempt to adjust the gap of a used plug.

   PREPARATION: 

   1. Install the spark plug to the ignition coil assembly.
   2. Disconnect the injector connector.
   3. Ground spark plug.
      Fig 1: Adjusting Gap Of Spark Plug

      Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

   CHECK: 

   Check if spark occurs while engine is being cracked.

   CAUTION: Always disconnect each injector connector.
   NOTE: Do not crank the engine for more than 2 seconds.

   OK: 

   Spark occurs across electrode gap. 

   1. OK: Go to step   8 . 
   2. NG: Go to next step 
6. Change normal spark plug and check spark of misfiring cylinder. 

   PREPARATION: 

   1. Change to the normal spark plug.
      1. Remove the spark plug that may be faulty from the ignition coil assembly.
      2. Install another spark plug to the ignition coil assembly.
   2. Disconnect the injector connector.
   3. Ground the spark plug.
      Fig 2: Checking Spark Of Misfiring Cylinder

      Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

   CHECK: 

   Check if spark occurs while the engine is being cranked.

   CAUTION: Always disconnect each injector connector.
   NOTE: Do not crank the engine for more than 2 seconds.

   OK: 

   Spark jumps across electrode gap. 

   1. OK: Replace spark plug. 
   2. NG: Go to next step 
7. Check for open and short in harness and connector between ignition coil and ECM. 

   Check the harness and connector between the ignition coil and the ECM (IGF terminal) connectors: 

   PREPARATION: 

   1. Disconnect the I1, I2, I3, I4, I5, I6, I7 or I8 ignition coil connector.
   2. Disconnect the E8 ECM connector.

   CHECK: 

   Check the resistance between the wire harness side connectors.

   Fig 3: Identifying Ignition Coil Connector Terminals

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

   OK: 

   Standard: 

   TESTER CONNECTION SPECIFIED CONDITION
   
   

   Tester Connection	Specified Condition
   Ignition coil (I1-2) - IGF1 (E8-24)	Below 1 Ω
   Ignition coil (I2-2) - IGF2 (E8-25)	Below 1 Ω
   Ignition coil (I3-2) - IGF1 (E8-24)	Below 1 Ω
   Ignition coil (I4-2) - IGF2 (E8-25)	Below 1 Ω
   Ignition coil (I5-2) - IGF1 (E8-24)	Below 1 Ω
   Ignition coil (I6-2) - IGF2 (E8-25)	Below 1 Ω
   Ignition coil (I7-2) - IGF1 (E8-24)	Below 1 Ω
   Ignition coil (I8-2) - IGF2 (E8-25)	Below 1 Ω
   Ignition coil (I1-2) or IGF1 (E8-24) - Body ground	10 kΩ or higher
   Ignition coil (I2-2) or IGF2 (E8-25) - Body ground	10 kΩ or higher
   Ignition coil (I3-2) or IGF1 (E8-24) - Body ground	10 kΩ or higher
   Ignition coil (I4-2) or IGF2 (E8-25) - Body ground	10 kΩ or higher
   Ignition coil (I5-2) or IGF1 (E8-24) - Body ground	10 kΩ or higher
   Ignition coil (I6-2) or IGF2 (E8-25) - Body ground	10 kΩ or higher
   Ignition coil (I7-2) or IGF1 (E8-24) - Body ground	10 kΩ or higher
   Ignition coil (I8-2) or IGF2 (E8-25) - Body ground	10 kΩ or higher

   Fig 4: Identifying E8 ECM Connector Terminals

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

   Check the harness and connector between the ignition coil and the ECM (IGT terminal) connectors: 

   PREPARATION: 

   1. Disconnect the I1, I2, I3, I4, I5, I6, I7 or I8 ignition coil connector.
   2. Disconnect the E8 ECM connector.

   CHECK: 

   Check the resistance between the wire harness side connectors.

   Fig 5: Identifying Ignition Coil Connector Terminals - Wire Harness Side

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

   OK: 

   Standard: 

   TESTER CONNECTION SPECIFIED CONDITION
   
   

   Tester Connection	Specified Condition
   Ignition coil (I1-3) - IGT1 (E8-8)	Below 1 Ω
   Ignition coil (I2-3) - IGT2 (E8-15)	Below 1 Ω
   Ignition coil (I3-3) - IGT3 (E8-11)	Below 1 Ω
   Ignition coil (I4-3) - IGT4 (E8-10)	Below 1 Ω
   Ignition coil (I5-3) - IGT5 (E8-13)	Below 1 Ω
   Ignition coil (I6-3) - IGT6 (E8-12)	Below 1 Ω
   Ignition coil (I7-3) - IGT7 (E8-14)	Below 1 Ω
   Ignition coil (I8-3) - IGT8 (E8-9)	Below 1 Ω
   Ignition coil (I1-3) or IGT1 (E8-8) - Body ground	10 kΩ or higher
   Ignition coil (I2-3) or IGT2 (E8-15) - Body ground	10 kΩ or higher
   Ignition coil (I3-3) or IGT3 (E8-11) - Body ground	10 kΩ or higher
   Ignition coil (I4-3) or IGT4 (E8-10) - Body ground	10 kΩ or higher
   Ignition coil (I5-3) or IGT5 (E8-13) - Body ground	10 kΩ or higher
   Ignition coil (I6-3) or IGT6 (E8-12) - Body ground	10 kΩ or higher
   Ignition coil (I7-3) or IGT7 (E8-14) - Body ground	10 kΩ or higher
   Ignition coil (I8-3) or IGT8 (E8-9) - Body ground	10 kΩ or higher

   Fig 6: Identifying E8 ECM Connector Terminals

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
   1. OK: Replace ignition coil with igniter, then confirm that there is no misfire. 
   2. NG: Repair or replace harness or connector. 
8. Check ECM terminal of misfiring cylinder. 

   PREPARATION: 

   Turn the ignition switch ON.

   CHECK: 

   Measure the voltage between the terminals of the E6 and E8 ECM connectors.

   OK: 

   Standard: 

   TESTER CONNECTION SPECIFIED CONDITION
   
   

   Tester Connection	Specified Condition
   #10 (E6-2) - E01 (E8-7)	9 to 14 V
   #20 (E6-3) - E01 (E8-7)	9 to 14 V
   #30 (E6-4) - E01 (E8-7)	9 to 14 V
   #40 (E6-5) - E01 (E8-7)	9 to 14 V
   #50 (E6-6) - E01 (E8-7)	9 to 14 V
   #60 (E6-7) - E01 (E8-7)	9 to 14 V
   #70 (E8-3) - E01 (E8-7)	9 to 14 V
   #80 (E8-2) - E01 (E8-7)	9 to 14 V

   Fig 7: Identifying E6 And E8 ECM Connector Terminals

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
   1. OK: Go to step   11 . 
   2. NG: Go to next step 
9. Check injector resistance of misfiring cylinder (See  INJECTOR  ). 
   1. NG: Replace injector. 
   2. OK: Go to next step 
10. Check for open and short in harness and connector between ignition SW and injector, injector and ECM of misfiring cylinder. 

    PREPARATION: 

    1. Disconnect the I9, I10, I11, I12, I13, I14, I15 or I16 injector connector.
    2. Disconnect the E6 or E8 ECM connector.

    CHECK: 

    Measure the resistance of the wire harness side connectors between the ECM and injector.

    OK: 

    Standard: 

    Fig 8: Identifying Injector Connector Terminals - Wire Harness Side

    Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    TESTER CONNECTION SPECIFIED CONDITION
    
    

    Tester Connection	Specified Condition
    Injector (I9-2) - #10 (E6-2)	Below 1 Ω
    Injector (I10-2) - #20 (E6-3)	Below 1 Ω
    Injector (I11-2) - #30 (E6-4)	Below 1 Ω
    Injector (I12-2) - #40 (E6-5)	Below 1 Ω
    Injector (I13-2) - #50 (E6-6)	Below 1 Ω
    Injector (I14-2) - #60 (E6-7)	Below 1 Ω
    Injector (I15-2) - #70 (E8-3)	Below 1 Ω
    Injector (I16-2) - #80 (E8-2)	Below 1 Ω
    Injector (I9-2) or #10 (E6-2) - Body ground	10 kΩ or higher
    Injector (I10-2) or #20 (E6-3) - Body ground	10 kΩ or higher
    Injector (I11-2) or #30 (E6-4) - Body ground	10 kΩ or higher
    Injector (I12-2) or #40 (E6-5) - Body ground	10 kΩ or higher
    Injector (I13-2) or #50 (E6-6) - Body ground	10 kΩ or higher
    Injector (I14-2) or #60 (E6-7) - Body ground	10 kΩ or higher
    Injector (I15-2) or #70 (E8-3) - Body ground	10 kΩ or higher
    Injector (I16-2) or #80 (E8-2) - Body ground	10 kΩ or higher

    Fig 9: Identifying E6 And E8 ECM Connector Terminals

    Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

    PREPARATION: 

    1. Disconnect the I9, I10, I11, I12, I13, I14, I15 or I16 injector connector.
    2. Disconnect the I18 ignition switch connector.

    CHECK: 

    Measure the resistance the wire harness side connectors between the injector and ignition switch.

    OK: 

    Standard: 

    Fig 10: Identifying Injector Connector Terminals - Wire Harness Side

    Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    TESTER CONNECTION SPECIFIED CONDITION
    
    

    Tester Connection	Specified Condition
    Injector (I9-1) - IG2 (I18-6)	Below 1 Ω
    Injector (I10-1) - IG2 (I18-6)	Below 1 Ω
    Injector (I11-1) - IG2 (I18-6)	Below 1 Ω
    Injector (I12-1) - IG2 (I18-6)	Below 1 Ω
    Injector (I13-1) - IG2 (I18-6)	Below 1 Ω
    Injector (I14-1) - IG2 (I18-6)	Below 1 Ω
    Injector (I15-1) - IG2 (I18-6)	Below 1 Ω
    Injector (I16-1) - IG2 (I18-6)	Below 1 Ω
    Injector (I9-1) or IG2 (I18-6) - Body ground	10 kΩ or higher
    Injector (I10-1) or IG2 (I18-6) - Body ground	10 kΩ or higher
    Injector (I11-1) or IG2 (I18-6) - Body ground	10 kΩ or higher
    Injector (I12-1) or IG2 (I18-6) - Body ground	10 kΩ or higher
    Injector (I13-1) or IG2 (I18-6) - Body ground	10 kΩ or higher
    Injector (I14-1) or IG2 (I18-6) - Body ground	10 kΩ or higher
    Injector (I15-1) or IG2 (I18-6) - Body ground	10 kΩ or higher
    Injector (I16-1) or IG2 (I18-6) - Body ground	10 kΩ or higher

    Fig 11: Identifying Connector Terminals Ignition Switch

    Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    1. NG: Repair or replace harness or connector. 
    2. OK: Go to next step 
11. Check injector injection of misfiring cylinder (See  INSPECTION  ). 
    1. NG: Replace injector. 
    2. OK: Go to next step 
12. Check compression pressure of misfiring cylinder (See  COMPRESSION  ). 
    1. NG: Repair or replace. 
    2. OK: Go to next step 
13. Check valve clearance of misfiring cylinder (See  VALVE CLEARANCE  ). 
    1. NG: Adjust valve clearance. 
    2. OK: Go to next step 
14. Switch step by number of misfire cylinder (Refer to the result of step   4 ). 
    HIGH MISFIRE RATE CYLINDER DESCRIPTION
    
    

    High misfire rate cylinder	Proceed to
    1 or 2 cylinders	A
    More than 3 cylinders	B

    1. B:  CHECK FOR INTERMITTENT PROBLEMS  
    2. A: Go to next step 
15. Check valve timing (Check for looseness or a jumped tooth of timing belt) (See  IGNITION TIMING  ). 
    1. NG: Adjust valve timing (Repair or replace timing belt). 
    2. OK: Go to next step 
16. Check fuel pressure (See  FUEL PUMP  ). 
    1. NG: Check and repair fuel pump, pressure regulator, fuel pipe line and filter (See  SFI SYSTEM  ). 
    2. OK: Go to next step 
17. Check intake air temperature and mass air flow rate. 

    PREPARATION: 

    1. Connect the hand-held tester to the DLC3.
    2. Turn the ignition switch ON.

    CHECK: 

    Check the intake air temperature.

    1. When using hand-held tester, enter the following menu: DIAGNOSIS / ENHANCED OBD II / DATA LIST / ALL / INTAKE AIR.
    2. Read its value displayed on the hand-held tester.

    OK: 

    Equivalent to ambient temperature 

    CHECK: 

    Check the air flow rate.

    1. When using hand-held tester, enter the following menu: DIAGNOSIS/ENHANCED OBD II/DATA LIST/ALL/MAF.
    2. Read its value displayed on the hand-held tester.

    OK: 

    AIR FLOW RATE DESCRIPTION
    
    

    Condition	Air Flow Rate (gm/s)
    Ignition switch ON (do not start engine)	0
    Idling	4 to 6
    Running without load (2,500 RPM)	13 to 20
    Idling to quickly accelerating	Air flow rate fluctuates

    1. NG: Replace mass air flow meter. 
    2. OK: Go to next step 
18. Check engine coolant temperature sensor. 

    PREPARATION: 

    Remove the engine coolant temperature sensor.

    CHECK: 

    Measure the resistance between the terminals of the engine coolant temperature sensor.

    Resistance: 

    TESTER CONNECTION SPECIFIED CONDITION
    
    

    Tester Connection	Specified Condition
    1 - 2	2.32 to 2.59 kΩ (20°C (68°F))
    1 - 2	0.310 to 0.326 kΩ (80°C (176°F))

    NOTE: In case of checking the engine coolant temperature sensor in the water, be careful not to allow water to go into the terminals. After checking, dry the sensor.

    HINT:

    Alternate procedure: Connect an ohmmeter to the installed engine coolant temperature sensor and read the resistance. Use an infrared thermometer to measure the engine temperature in the immediate vicinity of the sensor. Compare these values to the resistance/temperature graph. Change the engine temperature (by warming up or cooling down) and repeat the test.

    Fig 12: Checking Engine Coolant Temperature Sensor

    Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    1. NG: Replace engine coolant temperature sensor. 
    2. OK: Go to next step 
19. Switch step by number of misfire cylinder (Refer to the result of step   4 ). 
    HIGH MISFIRE RATE CYLINDER DESCRIPTION
    
    

    High misfire rate cylinder	Proceed to
    1 or 2 cylinders	A
    More than 3 cylinders	B

    1. B: Go to step   5 . 
    2. A:  CHECK FOR INTERMITTENT PROBLEMS