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 record 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 volume in the tank.
2. Improper fuel is used.
3. The spark plugs have been contaminated.
After finishing repairs, check the misfire counts of the cylinders ([Cylinder #1 Misfire Rate to Cylinder #6 Misfire Rate]).
Be sure to confirm that no misfiring cylinder DTCs are set again by conducting the confirmation driving pattern after finishing 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 misfire have occurred only while warming up the engine.
Extremely imbalanced drive wheel may cause misfire DTCs detection.

CHECK ANY OTHER DTCS OUTPUT (IN ADDITION TO MISFIRE CODES)

Connect a Techstream to the DLC3.
Turn the ignition switch ON.
Turn the tester ON.
Select the following menu items: Powertrain / Engine and ECT / Trouble Codes.

Read DTCs.

HINT:

Write down the DTCs.

Result

RESULT REFERENCE

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

HINT:

If any DTCs other than P0300, P0301, P0302, P0303, P0304, P0305 and P0306 are output, troubleshoot those DTCs first.

B: GO TO DTC CHART (See DIAGNOSTIC TROUBLE CODE CHART )

A: Go to next step

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

READ VALUE USING TECHSTREAM (CATALYST OT MF F/C)

Connect a Techstream to the DLC3.
Turn the ignition switch ON.
Turn the tester ON.
Select the following menu items: Powertrain / Engine and ECT / Data List / Catalyst OT MF F/C.

Read the value displayed on the tester.

Result

RESULT REFERENCE

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

B: Go to step 6

A: Go to next step

PERFORM ACTIVE TEST USING TECHSTREAM (PROHIBIT CAT OT F/C)
1. Connect a Techstream to the DLC3.
2. Turn the ignition switch 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.

READ VALUE USING TECHSTREAM (CYLINDER MISFIRE RATE)

Select the following menu items: Powertrain / Engine and ECT / Data List / Misfire / Cylinder #1 Misfire Rate, #2, #3, #4, #5 and #6
Read each value for Cylinder #1 Misfire Rate to #6 displayed on the tester. If no misfire counts occur in any cylinders, perform the following procedures:
1. Start the engine and let it idle.
2. Move the shift lever to the D position.
3. Check the Cylinder #1 Misfire Rate to #6.
4. If misfire counts are still not displayed, perform steps (c) and ( d).
Drive the vehicle with the Misfire RPM and Misfire Load noted in the "READ VALUE USING TECHSTREAM (MISFIRE RPM AND MISFIRE LOAD)" procedures above.

Read the Cylinder #1 Misfire Rate to #6 or DTCs displayed on the tester.

Result

RESULT REFERENCE

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 19

A: Go to next step

CHECK SPARK PLUG

Remove the ignition coil and the spark plug of the misfiring cylinder.
Measure the spark plug electrode gap.
Maximum gap:

1.0 to 1.1 mm (0.039 to 0.043 in.)

Fig 1: Identifying Spark Plug Electrode Gap
Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

Check the electrode for carbon deposits. Recommended spark plug:

RECOMMENDED SPARK PLUG

Manufacturer	Product
DENSO	K20HR-U11
NGK	LFR60C11

NOTE: If the electrode gap is larger than standard, replace the spark plug. Do not adjust the electrode gap.

Reinstall the ignition coil and the spark plug.

NG: REPLACE SPARK PLUG (See REMOVAL )

OK: Go to Next Step

CHECK FOR SPARKS AND IGNITION
1. Disconnect the fuel injector connectors to prevent the engine from starting.
  CAUTION: Always disconnect all fuel injector connectors.
  
  NOTE: Do not crank the engine for more than 2 seconds.
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.
  OK: Sparks jump across electrode gap.
6. Install the ignition coil.
7. Reconnect the fuel injector connectors.
NG: Go to step 31

OK: Go to Next Step
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

CHECK HARNESS AND CONNECTOR (ECM - FUEL INJECTOR)

Disconnect the fuel injector connector (of the misfiring cylinder).

Fig 2: Identifying Fuel Injector Connector And B3 ECM Connector

Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

Disconnect the B3 ECM connector.

Measure the voltage according to the value(s) in the table below.

Standard Voltage

STANDARD VOLTAGE

Cylinder	Tester Connection	Switch Condition	Specified Condition
No. 1	B11-2 - Body ground	Ignition switch ON	11 to 14 V
No. 2	B25-2 - Body ground	Ignition switch ON	11 to 14 V
No. 3	B10-2-1 -Body ground	Ignition switch ON	11 to 14 V
No. 4	B21-2 - Body ground	Ignition switch ON	11 to 14 V
No. 5	B9-2-1 - Body ground	Ignition switch ON	11 to 14 V
No. 6	B18-2-Body ground	Ignition switch ON	11 to 14 V

Turn the ignition switch OFF.

Measure the resistance according to the value(s) in the table below.

Standard Resistance

STANDARD RESISTANCE

Cylinder	Tester Connection	Condition	Specified Condition
No. 1	B11-1 -Body ground	Always	10 kΩ or higher
No. 1	B11-1 -B3-2(#10)	Always	Below 1 Ω.
No. 2	B25-1 - Body ground	Always	10 kΩ or higher
No. 2	B25-1 - B3-3 (#20)	Always	Below 1 Ω
No. 3	B10-1 -Body ground	Always	10 kΩ or higher
No. 3	B10-1 -B3-4(#30)	Always	Below 1 Ω
No. 4	B21-1 -Body ground	Always	10 kΩ. or higher
No. 4	B21-1 -B3-5(#40)	Always	Below 1 Ω.
No. 5	B9-1 - Body ground	Always	10 kΩ or higher
No. 5	B9-1 - B3-6 (#50)	Always	Below 1 Ω
No. 6	B18-1 - Body ground	Always	10 kΩ or higher
No. 6	B18-1 -B3-7(#60)	Always	Below 1 Ω.

NG: REPAIR OR REPLACE HARNESS OR CONNECTOR

OK: Go to Next Step

INSPECT ECM TERMINAL OF MISFIRING CYLINDER (#10, #20, #30, #40, #50 AND/OR #60 VOLTAGE)

Turn the ignition switch ON.

Measure the voltage according to the value(s) in the table below.

Standard Voltage

STANDARD VOLTAGE

Tester Connection	Switch Condition	Specified Condition
#10(B3-2)-E01(B1-7)	Ignition switch ON	11 to 14 V
#20(B3-3)-E01(B1-7)	Ignition switch ON	11 to 14 V
#30(B3-4)-E01(B1-7)	Ignition switch ON	11 to 14 V
#40(B3-5)-E01(B1-7)	Ignition switch ON	11 to 14 V
#50(B3-6)-E01(B1-7)	Ignition switch ON	11 to 14 V
#60(B3-7)-E01(B1-7)	Ignition switch ON	11 to 14 V

Fig 3: Identifying ECM Connectors

Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

NG: REPAIR OR REPLACE HARNESS OR CONNECTOR (BATTERY - ECM)

OK: Go to Next Step

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

OK: Go to Next Step
CHECK VALVE CLEARANCE OF MISFIRING CYLINDER
1. Check the valve clearance (see VALVE CLEARANCE ).
NG: ADJUST VALVE CLEARANCE (See ADJUSTMENT )

OK: Go to Next Step
CHECK AIR INDUCTION SYSTEM
1. Check the air induction system for vacuum leak.
  OK: No leak from air induction system.
NG: REPAIR OR REPLACE AIR INDUCTION SYSTEM

OK: Go to Next Step
CHECK VALVE TIMING (See INSPECTION PROCEDURE )
NG: ADJUST VALVE TIMING

OK: Go to Next Step
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
READ VALUE USING TECHSTREAM (COOLANT TEMP) (See INSPECTION PROCEDURE )
NG: REPLACE ENGINE COOLANT TEMPERATURE SENSOR (See REMOVAL )

OK: Go to Next Step
INSPECT MASS AIR FLOW METER
1. Inspection mass air flow meter (see REMOVAL ).
NG: REPLACE MASS AIR FLOW METER (See REMOVAL )

OK: REPLACE ECM (See REMOVAL )
CHECK AIR INDUCTION SYSTEM
1. Check the air induction system for vacuum leak.
  OK: No leak from air induction system.
NG: REPAIR OR REPLACE AIR INDUCTION SYSTEM

OK: Go to Next Step
CHECK VALVE TIMING (See INSPECTION PROCEDURE )
NG: ADJUST VALVE TIMING

OK: Go to Next Step
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
READ VALUE USING TECHSTREAM (COOLANT TEMP) (See INSPECTION PROCEDURE )
NG: REPLACE ENGINE COOLANT TEMPERATURE SENSOR (See REMOVAL )

OK: Go to Next Step
INSPECT MASS AIR FLOW METER
1. Inspection mass air flow meter (see REMOVAL ).
NG: REPLACE MASS AIR FLOW METER (See REMOVAL )

OK: Go to Next Step

CHECK SPARK PLUG

Remove the ignition coil and the spark plug of the misfiring cylinder.
Measure the spark plug electrode gap.
Maximum gap: 1.0 to 1.1 mm (0.039 to 0.043 in.)

Fig 4: Identifying Spark Plug Electrode Gap
Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

Check the electrode for carbon deposits.

Recommended spark plug:

RECOMMENDED SPARK PLUG

Manufacturer	Product
DENSO	K20HR-U11
NGK	LFR6C11

NOTE: If the electrode gap is larger than standard, replace the spark plug. Do not adjust the electrode gap.

Reinstall the ignition coil and the spark plug.

NG: REPLACE SPARK PLUG (See REMOVAL )

OK: Go to Next Step

CHECK FOR SPARKS AND IGNITION
1. Disconnect the fuel injector connectors to prevent the engine from starting.
  CAUTION: Always disconnect all fuel injector connectors.
  
  NOTE: Do not crank the engine for more than 2 seconds.
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.
  OK: Sparks jump across electrode gap.
6. Install the ignition coil.
7. Reconnect the fuel injector connectors.
NG: Go to step 31

OK: Go to Next Step
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

CHECK HARNESS AND CONNECTOR (ECM - FUEL INJECTOR)

Disconnect the fuel injector connector (of the misfiring cylinder).

Fig 5: Identifying Fuel Injector Connector And B3 ECM Connector

Disconnect the B3 ECM connector.

Measure the voltage according to the value(s) in the table below.

Standard Voltage

STANDARD VOLTAGE

Cylinder	Tester Connection	Switch Condition	Specified Condition
No. 1	B11-2-Body ground	Ignition switch ON	11 to 14 V
No. 2	B25-2 - Body ground	Ignition switch ON	11 to 14 V
No. 3	B10-2-1 -Body ground	Ignition switch ON	11 to 14 V
No. 4	B21-2-Body ground	Ignition switch ON	11 to 14 V
No. 5	B9-2-1 - Body ground	Ignition switch ON	11 to 14 V
No. 6	B18-2-Body ground	Ignition switch ON	11 to 14 V

Turn the ignition switch OFF.

Measure the resistance according to the value(s) in the table below.

Standard Resistance

STANDARD RESISTANCE

Cylinder	Tester Connection	Condition	Specified Condition
No. 1	B11-1 -Body ground	Always	10 kΩ or higher
No. 1	B11-1 -B3-2(#10)	Always	Below 1 Ω
No. 2	B25-1 - Body ground	Always	10 kΩ or higher
No. 2	B25-1 - B3-3 (#20)	Always	Below 1 Ω
No. 3	B10-1 -Body ground	Always	10 kΩ or higher
No. 3	B10-1-B3-4(#30)	Always	Below 1 Ω
No. 4	B21-1-Body ground	Always	10 kΩ or higher
No. 4	B21-1 -B3-5(#40)	Always	Below 1 Ω
No. 5	B9-1 - Body ground	Always	10 kΩ or higher
No. 5	B9-1 - B3-6 (#50)	Always	Below 1 Ω
No. 6	B18-1-Body ground	Always	10 kΩ or higher
No. 6	B18-1 -B3-7(#60)	Always	Below 1 Ω

NG: REPAIR OR REPLACE HARNESS OR CONNECTOR

OK: Go to Next Step

INSPECT ECM TERMINAL OF MISFIRING CYLINDER (#10, #20, #30, #40, #50 AND/OR #60 VOLTAGE)

Turn the ignition switch ON.

Measure the voltage according to the value(s) in the table below.

Standard Voltage

STANDARD VOLTAGE

Tester Connection	Switch Condition	Specified Condition
#10(B3-2)-E01(B1-7)	Ignition switch ON	11 to 14 V
#20(B3-3)-E01(B1-7)	Ignition switch ON	11 to 14 V
#30(B3-4)-E01(B1-7)	Ignition switch ON	11 to 14 V
#40(B3-5)-E01(B1-7)	Ignition switch ON	11 to 14 V
#50(B3-6)-E01(B1-7)	Ignition switch ON	11 to 14 V
#60(B3-7)-E01(B1-7)	Ignition switch ON	11 to 14 V

Fig 6: Identifying ECM Connectors

NG: REPAIR OR REPLACE HARNESS OR CONNECTOR (BATTERY - ECM)

OK: Go to Next Step

CHECK FUEL INJECTOR OF MISFIRING CYLINDER
1. Check the fuel injector injection (whether fuel volume is high or low, and whether injection pattern is poor) (see INSPECTION ).
NG: REPLACE FUEL INJECTOR ASSEMBLY (See REMOVAL )

OK: Go to Next Step
CHECK VALVE CLEARANCE OF MISFIRING CYLINDER
1. Check the valve clearance (see VALVE CLEARANCE ).
NG: ADJUST VALVE CLEARANCE

OK: REPLACE ECM (See REMOVAL )
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 fuel injector connectors.
  
  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 fuel 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 32

OK: REPLACE SPARK PLUG (See REMOVAL )
CHANGE TO NORMAL IGNITION COIL AND CHECK SPARK OF MISFIRING CYLINDER
1. Change the installed ignition coil to a ignition coil that functions normally.
2. Perform a spark test.
  CAUTION: Always disconnect all fuel injector connectors.
  
  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 fuel 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 ASSEMBLY (See REMOVAL )