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.

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

Connect the intelligent tester to the DLC3.
Turn the ignition switch to the ON position.
Turn the tester ON.
Select the following menu items: DIAGNOSIS / ENHANCED OBD II / DTC INFO / CURRENT CODES.

Read the DTCs.

HINT:

Write down indicated DTCs.

Result

DTC OUTPUT RESULT

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

A: Go to next step

READ VALUE USING INTELLIGENT TESTER (MISFIRE RPM AND MISFIRE LOAD)
1. Connect the intelligent tester to the DLC3.
2. Turn the ignition switch to the ON position.
3. Turn the tester ON.
4. Select the following menu items: DIAGNOSIS / ENHANCED OBD II / 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 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 INTELLIGENT TESTER (CAT OT MF F/C)

Connect the intelligent tester to the DLC3.
Turn the ignition switch to the ON position.
Turn the tester ON.
Select the following menu items: DIAGNOSIS / ENHANCED OBD II / DATA LIST / CAT OT MF F/C.

Read the value displayed on the tester.

Result

DTC OUTPUT RESULT

Data List	Tester Display	Proceed to
CAT OT MF F/C	AVAIL	A
CAT OT MF F/C	NOT AVL	B

B: Go to step 6

A: Go to next step

PERFORM ACTIVE TEST USING INTELLIGENT TESTER (PRHBT CAT OT F/C)
1. Connect the intelligent tester to the DLC3.
2. Turn the ignition switch to the ON position.
3. Turn the tester ON.
4. Select the following menu items: DIAGNOSIS / ENHANCED OBD II / ACTIVE TEST / PRHBT CAT OT FC.
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 INTELLIGENT TESTER (CYL #1, #2, #3 AND #4)

Select the following menu items: DIAGNOSIS / ENHANCED OBD II / DATA LIST / USER DATA / CYL #1, #2, #3 and #4.
Start the engine and allow the engine to idle.
Read each value for CYL #1 to #4 displayed on the tester. If no misfire counts occur in any cylinders, perform steps (d) and (e) and then check the misfire counts again.
Drive the vehicle with the MISFIRE RPM and MISFIRE LOAD noted in the "READ VALUE USING INTELLIGENT TESTER or TECH STREAM" procedures above.

Read the CYL #1 to #4 or DTCs displayed on the tester.

Result

DTC OUTPUT RESULT

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:

it is difficult to reproduce misfires for each cylinder, check the Data List item called MISFIRE MARGIN^*1 . Try to find vehicle driving conditions that lower the MISFIRE MARGIN^*1 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 ENG RUN TIME^*1 ? is below 120 seconds, the misfire may be detected immediately after the engine is started.
^*1 : Intelligent tester

B: Go to step 19

A: Go to next step

INSPECT SPARK PLUG

Remove the ignition coil and the spark plug from the misfiring cylinder.
Measure the spark plug electrode gap.
Standard 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 REFERENCE

Manufacturer	Product
DENSO	SK20R11

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

Reinstall the ignition coil.

NG: REPLACE SPARK PLUG

OK: Go to next step

CHECK FOR SPARKS 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. Attach the spark plug assembly to the cylinder head.
5. Crank the engine for less than 2 seconds and check the spark.
  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 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 WIRE HARNESS (INJECTOR - ECM)

Disconnect the injector connector (of the misfiring cylinder).

Fig 3: Identifying E7 ECM Connector Terminal

Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

Disconnect the E7 ECM connector.
Turn the ignition switch to the ON position.

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

Standard: Cylinder No. 1

TESTER CONNECTION AND SPECIFIED CONDITION

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

Cylinder No. 2

TESTER CONNECTION AND SPECIFIED CONDITION

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

Cylinder No. 3

TESTER CONNECTION AND SPECIFIED CONDITION

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

Cylinder No. 4

TESTER CONNECTION AND SPECIFIED CONDITION

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

NG: REPAIR OR REPLACE HARNESS OR CONNECTOR

OK: Go to next step

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

Turn the ignition switch to the ON position.

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

Standard voltage

VOLTAGE SPECIFIED CONDITION

Tester Connection	Switch Condition	Specified Condition
#1 (E7-6) - E01 (E8-7)	Ignition switch ON	11 to 14 V
#2 (E7-5) - E01 (E8-7)	Ignition switch ON	11 to 14 V
#3 (E7-2) - E01 (E8-7)	Ignition switch ON	11 to 14 V
#4 (E7-1) - E01 (E8-7)	Ignition switch ON	11 to 14 V

Fig 4: Identifying E7 And E8 ECM Connector Terminal

Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

NG: REPAIR OR REPLACE HARNESS OR CONNECTOR

OK: Go to next step

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

OK: Go to next step
CHECK VALVE CLEARANCE OF MISFIRING CYLINDER
1. Check the valve clearance (See VALVE CLEARANCE ).
NG: ADJUST VALVE CLEARANCE

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 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
READ VALUE USING INTELLIGENT TESTER (COOLANT TEMP)
NG: REPLACE ENGINE COOLANT TEMPERATURE SENSOR

OK: Go to next step
INSPECT MASS AIR FLOW METER
NG: REPLACE MASS AIR FLOW METER

OK: Go to next step
CHECK VALVE TIMING
NG: ADJUST VALVE TIMING

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
NG: ADJUST VALVE TIMING

OK: Go to next step
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
READ VALUE USING INTELLIGENT TESTER (COOLANT TEMP)
NG: REPLACE ENGINE COOLANT TEMPERATURE SENSOR

OK: Go to next step
INSPECT MASS AIR FLOW METER
NG: REPLACE MASS AIR FLOW METER

OK: Go to next step

INSPECT SPARK PLUG

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

1.0 to 1.1 mm (0.039 to 0.043 in.)

Fig 5: Identifying Spark Plug Electrode Gap
Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

Check the electrode for carbon deposits.

Recommended spark plug:

RECOMMENDED SPARK PLUG REFERENCE

Manufacturer	Product
DENSO	SK20R11

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

Reinstall the ignition coil.

NG: REPLACE SPARK PLUG

OK: Go to next step

CHECK FOR SPARKS 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. Attach the spark plug assembly to the cylinder head.
5. Crank the engine for less than 2 seconds and check the spark.
  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 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 WIRE HARNESS (INJECTOR - ECM)

Disconnect the injector connector (of the misfiring cylinder).

Fig 7: Identifying E7 ECM Connector Terminal

Disconnect the E7 ECM connector.
Turn the ignition switch to the ON position.

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

Standard:

Cylinder No. 1

TESTER CONNECTION AND SPECIFIED CONDITION

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

Cylinder No. 2

TESTER CONNECTION AND SPECIFIED CONDITION

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

Cylinder No. 3

TESTER CONNECTION AND SPECIFIED CONDITION

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

Cylinder No. 4

TESTER CONNECTION AND SPECIFIED CONDITION

Tester Connection	Specified Condition
F4-1 - Body ground	11 to 14 V
F4-2 - Body 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

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

Turn the ignition switch to the ON position.

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

Standard voltage

VOLTAGE SPECIFIED CONDITION

Tester Connection	Switch Condition	Specified Condition
#1 (E7-6) - E01 (E8-7)	Ignition switch ON	11 to 14 V
#2 (E7-5) - E01 (E8-7)	Ignition switch ON	11 to 14 V
#3 (E7-2) - E01 (E8-7)	Ignition switch ON	11 to 14 V
#4 (E7-1) - E01 (E8-7)	Ignition switch ON	11 to 14 V

Fig 8: Identifying E7 And E8 ECM Connector Terminal

NG: REPAIR OR REPLACE HARNESS OR CONNECTOR

OK: Go to next step

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

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 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: Go to step 32

OK: REPLACE SPARK PLUG
CHANGE TO NORMAL IGNITION COIL AND CHECK SPARK OF MISFIRING CYLINDER
1. Change the ignition coil to a ignition coil that functions normally.
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 REMOVAL )

OK: REPLACE IGNITION COIL