Inspection Procedure

HINT:

If DTCs besides misfire DTCs are memorized simultaneously, troubleshoot the non-misfire DTCs first.
Read freeze frame data using the intelligent tester. Freeze frame data records the engine condition when malfunction is detected. When troubleshooting, freeze frame data can help determine if the vehicle was running or stopped, 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 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 repairs, confirm that there is no misfire (see confirmation driving pattern).
When either of SHORT FT #1 and LONG FT #1 in the freeze frame data is over the range of +-20%, there is a possibility that the air-fuel ratio is inclining either to 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 reason may be because of the driving the vehicle with lack of fuel, use of improper fuel, a stain on the ignition plug, etc.
Be sure to check the value on the misfire counter after repairs.

CHECK OTHER DTC OUTPUT (IN ADDITION TO MISFIRE DTCS)

Connect the intelligent tester to the DLC3.
Turn the power switch ON (IG).
Turn the intelligent tester ON.
Enter the following menus: DIAGNOSIS / ENHANCED OBD II / DTC INFO / CURRENT CODES.

Read DTCs.

Result

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 other codes besides P0300, P0301, P0302, P0303 or P0304 are output, perform troubleshooting for those DTCs first.

B : GO TO RELEVANT DTC CHART

A : Go to Next Step

CHECK WIRE HARNESS, CONNECTOR AND VACUUM HOSE IN ENGINE ROOM
1. Check the connection conditions of the wire harness and connectors.
2. Check the vacuum hose piping for disconnection or breakage.
  OK : Connected correctly and no damage on wire harness.
NG : REPAIR OR REPLACE, THEN CONFIRM THAT THERE IS NO MISFIRE

OK : GO TO NEXT STEP
CHECK CONNECTION OF PCV HOSE
OK : PCV hose is connected correctly, and has no damage.

NG : REPAIR OR REPLACE PCV HOSE

OK : GO TO NEXT STEP

READ VALUE OF INTELLIGENT TESTER (NUMBER OF MISFIRE CYLINDER)

Connect the intelligent tester to the DLC3.
Turn the power switch ON (IG).
Turn the intelligent tester ON.
Put the engine in inspection mode (see PRECAUTION ).
Start the engine.
Enter the following menus: DIAGNOSIS / ENHANCED OBD II / DATA LIST / USER DATA / CYL#1 - CYL#4.

Read the number of misfire cylinders on the intelligent tester.

Result

RESULT REFERENCE

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

B : Go to step 15

A : Go to Next Step

CHECK SPARK PLUG AND SPARK OF MISFIRING CYLINDER
1. Remove the ignition coil.
2. Remove the spark plug.
3. Check the spark plug type.
  Recommended spark plug:
  RECOMMENDED SPARK PLUG REFERENCE
  
  DENSO made SK16R11
4. Check the spark plug electrode gap.
  Electrode gap: 0.7 to 0.8 mm (0.028 to 0.032 in.)
  
  Maximum electrode gap: 1.16 mm (0.046 in.)
  
  NOTE: If adjusting the gap of a new spark plug, bend only the base of the ground electrode. Do not touch the tip. Never attempt to adjust the gap on the used plug.
5. Check the electrode for carbon deposits.
6. Perform a spark test.
  
  Fig 1: Checking Spark Plug Electrode Gap
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
  
  CAUTION: Absolutely disconnect the 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 spark occurs while the engine is being cranked.
    OK : Spark jumps across electrode gap.
7. Reinstall the spark plug.
8. Reinstall the ignition coil.
OK : Go to step 8

NG : GO TO NEXT STEP
CHANGE NORMAL SPARK PLUG AND CHECK SPARK OF MISFIRING CYLINDER
1. Change to the normal spark plug.
2. Perform a spark test.
  CAUTION: Absolutely 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 spark occurs while the engine is being cranked.
    OK : Spark jumps across electrode gap.
OK : REPLACE SPARK PLUG

NG : GO TO NEXT STEP

CHECK HARNESS AND CONNECTOR OF MISFIRING CYLINDER (IGNITION COIL - ECM)

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

Fig 2: Disconnecting E4 ECM Connector

Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

Disconnect the I1, I2, I3 or I4 ignition coil connector.
Disconnect the E4 ECM connector.

Measure the resistance between the wire harness side connectors.

Standard resistance (Check for open)

Fig 3: Identifying Ignition Coil Connector

Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

TESTER CONNECTION AND SPECIFIED CONDITION

Tester Connection	Specified Condition
I1-2 (IGf) - E4-23 (IGF)	Below 1 Ω
I2-2 (IGf) - E4-23 (IGF)	Below 1 Ω
I3-2 (IGf) - E4-23 (IGF)	Below 1 Ω
I4-2 (IGf) - E4-23 (IGF)	Below 1 Ω

Standard resistance (Check for short)

TESTER CONNECTION AND SPECIFIED CONDITION

Tester Connection	Specified Condition
I1-2 (IGf) or E4-23 (IGF) - Body ground	10 kΩ or higher
I2-2 (IGf) or E4-23 (IGF) - Body ground	10 kΩ or higher
I3-2 (IGf) or E4-23 (IGF) - Body ground	10 kΩ or higher
I4-2 (IGf) or E4-23 (IGF) - Body ground	10 kΩ or higher

Reconnect the ignition coil connector.
Reconnect the ECM connector.

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

Fig 4: Disconnecting E4 ECM Connector

Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

Disconnect the I1, I2, I3 or I4 ignition coil connector.
Disconnect the E4 ECM connector.

Measure the resistance between the wire harness side connectors.

Standard resistance (Check for open)

Fig 5: Identifying Ignition Coil Connector

Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

TESTER CONNECTION AND SPECIFIED CONDITION

Tester Connection	Specified Condition
I1-3 (IGt) - E4-8 (IGT1)	Below 1 Ω
I2-3 (IGt) - E4-9 (IGT2)	Below 1 Ω
I3-3 (IGt) - E4-10 (IGT3)	Below 1 Ω
I4-3 (IGt) - E4-11 (IGT4)	Below 1 Ω

Standard resistance (Check for short)

TESTER CONNECTION AND SPECIFIED CONDITION

Tester Connection	Specified Condition
I1-3 (IGt) or E4-8 (IGT1) - Body ground	10 kΩ or higher
I2-3 (IGt) or E4-9 (IGT2) - Body ground	10 kΩ or higher
I3-3 (IGt) or E4-10 (IGT3) - Body ground	10 kΩ or higher
I4-3 (IGt) or E4-11 (IGT4) - Body ground	10 kΩ or higher

Reconnect the ignition coil connector.
Reconnect the ECM connector.

OK : REPLACE IGNITION COIL (THEN CONFIRM THAT THERE IS NO MISFIRE)

NG : REPAIR OR REPLACE HARNESS AND CONNECTOR

CHECK ECM TERMINAL OF MISFIRING CYLINDER (#10. #20. #30 OR #40 VOLTAGE)

Turn the power switch ON (IG).

Measure the voltage between the applicable terminals of the E4 ECM connector.

Standard voltage

TESTER CONNECTION AND SPECIFIED CONDITION

Tester Connection	Specified condition
E4-2 (#10) - E4-7 (E01)	9 to 14 V
E4-3 (#20) - E4-7 (E01)	9 to 14 V
E4-4 (#30) - E4-7 (E01)	9 to 14 V
E4-5 (#40) - E4-7 (E01)	9 to 14 V

OK : Go to step 11

Fig 6: Identifying ECM Connector

Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

NG : GO TO NEXT STEP

INSPECT FUEL INJECTOR RESISTANCE OF MISFIRING CYLINDER
NG : REPLACE FUEL INJECTOR ASSEMBLY

OK : GO TO NEXT STEP

CHECK HARNESS AND CONNECTOR OF MISFIRING CYLINDER (INJECTOR - ECM, INJECTOR - IG2 RELAY)

Check the harness and connectors between the injector connector and ECM connector.

Fig 7: Identifying Injector Connector

Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

Disconnect the I5, I6, I7 or I8 injector connector.
Disconnect the E4 ECM connector.

Measure the resistance between the wire harness side connectors.

Standard resistance (Check for open)

Fig 8: Disconnecting E4 ECM Connector

Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

TESTER CONNECTION AND SPECIFIED CONDITION

Tester Connection	Specified Condition
I5-2 (Injector) - E4-2 (#10)	Below 1 Ω
I6-2 (Injector) - E4-3 (#20)	Below 1 Ω
I7-2 (Injector) - E4-4 (#30)	Below 1 Ω
I8-2 (Injector) - E4-5 (#40)	Below 1 Ω

Standard resistance (Check for short)

TESTER CONNECTION AND SPECIFIED CONDITION

Tester Connection	Specified Condition
I5-2 (Injector) or E4-2 (#10) - Body ground	10 kΩ or higher
I6-2 (Injector) or E4-3 (#20) - Body ground	10 kΩ or higher
I7-2 (Injector) or E4-4 (#30) - Body ground	10 kΩ or higher
I8-2 (Injector) or E4-5 (#40) - Body ground	10 kΩ or higher

Reconnect the injector connector.
Reconnect the ECM connector.

Check the harness and connectors between the injector connector and IG2 relay.

Disconnect the I5, I6, I7 or I8 injector connector.
Remove the integration relay from the engine room relay block.

Measure the resistance between the wire harness side connectors.

Standard resistance (Check for open)

TESTER CONNECTION AND SPECIFIED CONDITION

Tester Connection	Specified Condition
I5-1 (Injector) - 3I-4 (IG2 relay)	Below 1 Ω
I6-1 (Injector) - 3I-4 (IG2 relay)	Below 1 Ω
I7-1 (Injector) - 3I-4 (IG2 relay)	Below 1 Ω
I8-1 (Injector) - 3I-4 (IG2 relay)	Below 1 Ω

Fig 9: Removing Integration Relay From Engine Room Relay Block

Standard resistance (Check for short)

TESTER CONNECTION AND SPECIFIED CONDITION

Tester Connection	Specified Condition
I5-1 (Injector) or 3I-4 (IG2 relay) - Body ground	10 kΩ or higher
I6-1 (Injector) or 3I-4 (IG2 relay) - Body ground	10 kΩ or higher
I7-1 (Injector) or 3I-4 (IG2 relay) - Body ground	10 kΩ or higher
I8-1 (Injector) or 3I-4 (IG2 relay) - Body ground	10 kΩ or higher

Reconnect the injector connector.
Reinstall the integration relay connector.

NG : REPAIR OR REPLACE HARNESS AND CONNECTOR

OK : GO TO NEXT STEP

INSPECT FUEL INJECTOR INJECTION AND VOLUME OF MISFIRING CYLINDER
OK : Injection volume: 36 to 46 cm ³ (2.1 to 2.8 cu in.) per 15 seconds.

NG : REPLACE FUEL INJECTOR ASSEMBLY

OK : GO TO NEXT STEP
CHECK CYLINDER COMPRESSION PRESSURE OF MISFIRING CYLINDER
OK : Compression pressure: 728 kPa (7.4 kgf/cm ² , 106 psi) Minimum pressure: 537 kPa (5.4 kgf/cm ² , 77 psi)

NG : REPAIR OR REPLACE

OK : GO TO NEXT STEP
CHECK VALVE CLEARANCE OF MISFIRING CYLINDER
OK : Valve clearance (cold):

Intake: 0.17 to 0.23 mm (0.007 to 0.009 in.)

Exhaust: 0.27 to 0.33 mm (0.011 to 0.013 in.)

NG : ADJUST VALVE CLEARANCE

OK : GO TO NEXT STEP
SWITCH STEP BY NUMBER OF MISFIRE CYLINDER
HINT:
- If the "1 or 2 cylinders", proceed to A.
- If the "more than 3 cylinders", proceed to B.
B : CHECK FOR INTERMITTENT PROBLEMS

A : Go to Next Step
CHECK VALVE TIMING (CHECK FOR LOOSENESS OR A JUMPED TOOTH OF THE TIMING CHAIN)
OK : The match marks of crankshaft pulley and camshaft pulley are aligning.

NG : ADJUST VALVE TIMING (REPAIR OR REPLACE TIMING CHAIN)

OK : GO TO NEXT STEP
CHECK FUEL PRESSURE
OK : Fuel pressure: 304 to 343 kPa (3.1 to 3.5 kgf/cm ² , 44 to 50 psi)

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

OK : GO TO NEXT STEP

READ VALUE OF INTELLIGENT TESTER (INTAKE AIR TEMPERATURE AND MASS AIR FLOW RATE)

Connect the intelligent tester to the DLC3.
Turn the power switch ON (IG).
Turn the intelligent tester ON.
Check the intake air temperature.
1. Enter the following menus: DIAGNOSIS / ENHANCED OBD II / DATA LIST / PRIMARY / INTAKE AIR.
2. Read the value.
  Temperature: Equivalent to ambient air temperature.

Check the air flow rate.

Enter the following menus: DIAGNOSIS / ENHANCED OBD II / DATA LIST / PRIMARY / MAF.

Read the value.

AIR FLOW RATE SPECIFICATION

Condition	Air flow rate (g/sec.)
Power switch ON (do not start engine)	0.0
Idling (Inspection mode)	3.2 to 4.7
Running without load (Inspection mode, engine speed of 2,500 rpm)	13.1 to 18.9
During vehicle running (Vehicle speed of more than 38 mph)	Air flow rate fluctuates

NG : REPLACE MASS AIR FLOW METER

OK : GO TO NEXT STEP

INSPECT ENGINE COOLANT TEMPERATURE SENSOR (RESISTANCE)

Remove the engine coolant temperature sensor.

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

Standard resistance

TESTER CONNECTION AND SPECIFIED CONDITION

Tester Connection	Specified Condition
1 - 2	2 to 3 kΩ at 20°C (68°F)
1 - 2	0.2 to 0.4 kΩ at 80°C (176°F)

NOTE: When checking the engine coolant temperature sensor in water, be careful not to allow water to contact 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 (warm up or allow to cool down) and repeat the test.

NG : REPLACE ENGINE COOLANT TEMPERATURE SENSOR

Fig 10: Engine Coolant Temperature Sensor Resistance Graph

OK : GO TO NEXT STEP

SWITCH STEP BY NUMBER OF MISFIRE CYLINDER
HINT:
- If the "1 or 2 cylinders", proceed to A.
- If the "more than 3 cylinders", proceed to B.
B : Go to step 5

A : CHECK FOR INTERMITTENT PROBLEMS