Inspection Procedure

WARNING: This page is about a different car, the 2007 Toyota RAV4. However, it is still accessible from the selected car via links, so may be relevant.

HINT:

If any DTCs other than misfire DTCs are output, troubleshoot those DTCs first.
Read freeze frame data using the intelligent tester. Freeze frame data records 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 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 level is low.
2. Improper fuel is used.
3. The spark plugs are dirty.
4. The problem is complex due to multiple factors.
After finishing repairs, check that no misfires occur in each cylinder (CYL #1, #2, #3, #4, #5 and #6).
Be sure to confirm that no misfiring cylinder DTCs are set again by conducting the confirmation driving pattern, after the repairs.
For 6 and 8 cylinder engines, the ECM intentionally does not set the specific misfiring cylinder DTCs at high engine RPM. If misfires only occur during high engine RPM driving, 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 either SHORT FT #1 or LONG FT #1 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 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 ON.
Turn the tester ON.
Select the following menu items: DIAGNOSIS / ENHANCED OBD II / DTC INFO / CURRENT CODES.
Read DTCs.

Result

RESULT CHART

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

A: GO to Next Step

READ VALUE USING INTELLIGENT TESTER (MISFIRE RPM AND MISFIRE LOAD)
1. Connect the intelligent tester the DLC3.
2. Turn the ignition switch 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.
CHECK PCV HOSE CONNECTIONS
OK: PCV hose is connected correctly and is not damaged.

NG: REPAIR OR REPLACE PCV HOSE

OK: GO to Next Step

CHECK MISFIRE COUNT (CYL #1, #2, #3, #4, #5 AND #6)

Connect the intelligent tester to the DLC3.
Turn the ignition switch ON.
Turn the tester ON.
Clear DTCs (see DTC CHECK/CLEAR ).
Select the following menu items: DIAGNOSIS / ENHANCED OBD II / DATA LIST / MISFIRE / CYL #1, #2, #3, #4, #5 and #6.
Allow the engine to idle.
Read each value for CYL #1 to #6 displayed on the tester. If no misfire counts occur in any cylinders, perform the following procedures:
1. Shift the gear selector lever to the D position.
2. Check the CYL #1 to #6.
3. If misfire counts are still not displayed, perform steps (h) and (i) 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 (MISFIRE RPM AND MISFIRE LOAD)" procedures above.
Read the CYL #1 to #6 or DTCs displayed on the tester.

Result

RESULT CHART

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 14

A: GO to Next Step

PERFORM ACTIVE TEST USING INTELLIGENT TESTER (FUEL CUT #1 TO #6)

Allow the engine to idle.
Select the following menu items: DIAGNOSIS / ENHANCED OBD II / ACTIVE TEST / FUEL CUT#1 (to #6).
If a cylinder has a high misfire count, cut fuel to that cylinder. Compare the misfire count of the cylinder before fuel cut and after fuel cut.

Result

RESULT CHART

Misfire Count in Each Cylinder	Proceed to
Misfire count of cylinder before fuel cut and after fuel cut roughly same	A
Misfire count of cylinder before fuel cut lower than after fuel cut	B

NOTE: This ACTIVE TEST cannot be performed while the vehicle is being driven.

HINT:

If the misfire count of the cylinder before and after the fuel cut are roughly the same, the cylinder is misfiring. If the misfire count of the cylinder before the fuel cut is lower than after the fuel cut, the cylinder misfires sometimes.

B: GO to step 11

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.
Standard gap: 1.0 to 1.1 mm (0.039 to 0.043 in.)
Check the electrode for carbon deposits.

Recommended spark plug:

SPARK PLUG SPECIFICATION

Manufacturer	Product
DENSO	FK20HR11

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

NG: REPLACE SPARK PLUG

Fig 1: Identifying Spark Plug Electrode Gap

Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

OK: GO to Next Step

CHECK FOR SPARKS AND IGNITION
1. Disconnect the injector connectors to prevent the engine from starting.
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 injector connectors.
NG: GO to step 9

Fig 2: Attaching Spark Plug Assembly To Cylinder Head
Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

OK: GO to Next Step
CHECK CYLINDER COMPRESSION PRESSURE OF MISFIRING CYLINDER
1. Measure the cylinder compression pressure of the misfiring cylinder.
OK: GO to step 10

NG: CHECK ENGINE TO DETERMINE CAUSE OF LOW COMPRESSION
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 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.

NG: REPLACE IGNITION COIL ASSEMBLY THEN CONFIRM THAT THERE IS NO MISFIRE

OK: REPLACE SPARK PLUG

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

Disconnect the B30 ECM connector.
Turn the ignition switch ON.
Measure the voltage between the terminals of the ECM connector.

Standard voltage

TESTER CONNECTION SPECIFIED CONDITION

Tester Connection	Specified Condition
B30-45 (#10) - B30-22 (E01)	9 to 14 V
B30-85 (#20) - B30-22 (E01)	9 to 14 V
B30-44 (#30) - B30-22 (E01)	9 to 14 V
B30-84 (#40) - B30-22 (E01)	9 to 14 V
B30-43 (#50) - B30-22 (E01)	9 to 14 V
B30-83 (#60) - B30-22 (E01)	9 to 14 V

OK: GO to step 12

Fig 3: Identifying B30 ECM Connector Terminals

NG: GO to Next Step

CHECK WIRE HARNESS (INJECTOR - ECM)

Disconnect the injector connector (of the misfiring cylinder).
Disconnect the B30 ECM connector.
Turn the ignition switch ON.

Measure the resistance and voltage between the injector and the ECM connector terminals.

Standard voltage

TESTER CONNECTION SPECIFIED CONDITION

Cylinder	Tester Connection	Specified Condition
No. 1	B53-2 - Ground	9 to 14 V
No. 2	B37-2 - Ground	9 to 14 V
No. 3	B52-2 - Ground	9 to 14 V
No. 4	B36-2 - Ground	9 to 14 V
No. 5	B51-2- Ground	9 to 14 V
No. 6	B35-2 - Ground	9 to 14 V

Fig 4: Identifying B30 ECM Connector Terminals

Standard resistance

TESTER CONNECTION SPECIFIED CONDITION

Cylinder	Tester Connection	Specified Condition
No. 1	B53-1 - Ground	10 kΩ or higher
No. 1	B53-1 - B30-45 (#10)	Below 1 Ω
No. 2	B37-1 - Ground	10 kΩ or higher
No. 2	B37-1 - B30-85 (#20)	Below 1 Ω
No. 3	B52-1 - Ground	10 kΩ or higher
No. 3	B52-1 - B30-44 (#30)	Below 1 Ω
No. 4	B36-1 - Ground	10 kΩ or higher
No. 4	B36-1 - B30-84 (#40)	Below 1 Ω
No. 5	B51 -1 - Ground	10 kΩ or higher
No. 5	B51-1 - B30-43(#50)	Below 1 Ω
No. 6	B35-1 - Ground	10 kΩ or higher
No. 6	B35-1 - B30-83 (#60)	Below 1 Ω

Reconnect the injector connector.
Reconnect the ECM connector.

NG: REPAIR OR REPLACE HARNESS AND 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 ASSEMBLY

OK: GO to Next Step
CHECK VALVE CLEARANCE OF MISFIRING CYLINDER
NG: ADJUST VALVE CLEARANCE

OK: GO to Next Step
CHECK AIR INDUCTION SYSTEM
1. Check the air induction system for vacuum leakage.
OK: No leakage 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 INTELLIGENT TESTER (COOLANT TEMP) (see INSPECTION PROCEDURE )
NG: REPLACE ENGINE COOLANT TEMPERATURE SENSOR

OK: GO to Next Step
READ VALUE USING INTELLIGENT TESTER (MAF) (see INSPECTION PROCEDURE )
NG: REPLACE MASS AIR FLOW METER

OK: CHECK FOR INTERMITTENT PROBLEMS