Toyota Tundra. Manual — part 1365

b. Improper fuel is used.

c. The spark plugs are dirty.



After finishing repairs, check that no misfires occur in each cylinder (cylinder No. 1, No. 2, No. 3, No. 4,
No. 5, No. 6, No. 7 and No. 8).



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:

a. Clear the DTC. (See DTC CHECK/CLEAR ).

b. Start the engine and conduct the confirmation driving pattern.

c. Read the misfiring rates of each cylinder or DTC (s) using the Techstream.

d. Repair the cylinder (s) that has a high misfiring rate or is indicated by the DTC.

e. After finishing repairs, conduct the confirmation driving pattern again, in order to verify that DTC

P0300 is not set.



When either 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 occurred only
while warming up the engine.



An extremely imbalanced drive wheel can cause body vibration, which may cause misfire DTC (s) to be
stored.

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

a. Connect the Techstream to the DLC3.

b. Turn the ignition switch to ON.

c. Turn the Techstream ON.

d. Enter the following menus: Powertrain/Engine and ECT/Trouble Codes.

e. Read DTCs.

Result

RESULT REFERENCE

HINT:

If any DTCs other than P0300, P0301, P0302, P0303, P0304, P0305, P0306, P0307 and P0308 are
output, troubleshoot those DTCs first.

Result

Proceed

To

P0300, P0301, P0302, P0303, P0304, P0305, P0306, P0307 and/or P0308 are output

A

P0300, P0301, P0302, P0303, P0304, P0305, P0306, P0307 and/or P0308 and other
DTCs are output

B

2008 Toyota Tundra

2008 ENGINE PERFORMANCE Engine Control System (2UZ-FE) - Tundra

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

A : Go To Next Step

2. READ VALUE USING TECHSTREAM (MISFIRE RPM AND MISFIRE LOAD)

a. Connect the Techstream the DLC3.

b. Turn the ignition switch to ON and turn the Techstream ON.

c. Enter the following menus: Powertrain/Engine and ECT/Data List/Misfire/Misfire RPM and

Misfire Load.

d. 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.

3. CHECK PCV HOSE CONNECTIONS

OK: PCV hose is connected correctly and is not damaged.

NG : REPAIR OR REPLACE PCV HOSE . (See PCV VALVE ).

OK : Go To Next Step

4. READ VALUE USING TECHSTREAM (MISFIRE COUNT)

a. Connect the Techstream to the DLC3.

b. Turn the ignition switch to ON.

c. Turn the Techstream ON.

d. Clear DTCs. (See DTC CHECK/CLEAR ).

e. Enter the following menus Powertrain/Engine and ECT/Data List/Misfire/Cylinder #1 Misfire Rate,

#2, #3, #4, #5, #6, #7 and #8.:

f. Allow the engine to idle.

g. Read each value for Cylinder #1 Misfire Rate to #8 displayed on the Techstream. If no misfire

counts occur in any cylinders, perform the following procedures:

1. Move the shift lever to the D position.

2. Check the Cylinder #1 Misfire Rate to #8.

3. If misfire counts are still not displayed, perform procedure "A" and "B" and then check the

misfire counts again.

h. Drive the vehicle with the Misfire RPM and Misfire Load noted in the "READ VALUE USING

Techstream (Misfire RPM AND Misfire Load)" procedures above. (Procedure "A")

i. Read the Cylinder #1 Misfire Rate to #8 or DTCs displayed on the Techstream. (Procedure "B")

Result

2008 Toyota Tundra

2008 ENGINE PERFORMANCE Engine Control System (2UZ-FE) - Tundra

RESULT REFERENCE

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 17

A : Go To Next Step

5. CHECK SPARK PLUG

a. Remove the ignition coil and the spark plug of the misfiring cylinder. (See REMOVAL ).

b. Measure the spark plug electrode gap.

Standard gap:

1.0 to 1.1 mm (0.0394 to 0.0433 in.)

c. Check the electrode for carbon deposits.

Recommended spark plug:

SPARK PLUG GAP SPECIFICATION

Result

Proceed To

Most misfires occur in only 1 or 2 cylinders

A

3 cylinders or more have equal misfire counts

B

Manufacturer Product

DENSO

SK20R11

NGK

IFR6A11

NOTE:

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

2008 Toyota Tundra

2008 ENGINE PERFORMANCE Engine Control System (2UZ-FE) - Tundra

Fig. 109: Identifying Spark Plug Electrode Gap

NG : REPLACE SPARK PLUG . (See IGNITION COIL SPARK PLUG ).

OK : Go To Next Step

6. CHECK FOR SPARKS AND IGNITION

a. Disconnect the injector connectors to prevent the engine from starting.

b. Remove the ignition coil from the cylinder head. (See REMOVAL ).

c. Install the spark plug onto the ignition coil.

d. Attach the spark plug assembly to the cylinder head.

e. Crank the engine for less than 2 seconds and check the spark.

Fig. 110: Checking For Sparks & Ignition

OK: Sparks jump across electrode gap.

f. Install the ignition coil.

g. Reconnect the injector connectors.

NG : Go to step 29

CAUTION: Always disconnect all injector connectors.

NOTE:

Do not crank the engine for more than 2 seconds.

2008 Toyota Tundra

2008 ENGINE PERFORMANCE Engine Control System (2UZ-FE) - Tundra