2Tr-Fe Engine Control. Dtc P0300 Random / Multiple Cylinder Misfire Detected

When the engine misfires, high concentrations of hydrocarbons (HC) enter the exhaust gas. Extremely high HC concentration levels can cause increases in exhaust emissions levels. High concentrations of HC can also cause increases in the Three-way Catalytic Converter (TWC) temperature, which may cause damage to the Three-way Catalytic Converter (TWC). To prevent these increases in emissions and to limit the possibility of thermal damage, the ECM monitors the misfire rate. When the temperature of the Three-way Catalytic Converter (TWC) reaches the point of thermal degradation, the MIL blinks. To monitor misfires, the ECM uses both the camshaft position sensor and the crankshaft position sensor. The camshaft position sensor is used to identify any misfiring cylinders and the crankshaft position sensor is used to measure variations in the crankshaft rotation speed. Misfires are counted as when the crankshaft rotation speed variations exceed predetermined thresholds.
If the misfire rate exceeds the threshold, the ECM illuminates the MIL and stores a DTC.

DTC No.	DTC Detection Condition	Trouble Area
P0300	Simultaneous misfiring of several cylinders occurs and one of the following conditions below is detected (2 trip detection logic): Misfire occurs that may damage the three-way catalytic converter (MIL blinks when detect immediately). Catalyst deterioration misfire occurs (MIL illuminates).	Open or short in engine wire harness Connector connection Vacuum hose connections Ignition system Fuel injector assembly Fuel pressure Mass air flow meter Engine coolant temperature sensor Compression pressure Valve timing PCV valve and hose PCV hose connections Air induction system ECM
P0301 P0302 P0303 P0304	Misfiring of specific cylinder occurs and one of the following conditions below is detected (2 trip detection logic): Misfire occurs that may damage the three-way catalytic converter (MIL blinks when detect immediately). Catalyst deterioration misfire occurs (MIL illuminates).

When multiple DTCs for misfiring cylinders are stored, but DTC P0300 is not stored, it indicates that misfires have been detected in different cylinders at different times. DTC P0300 is only stored when several misfiring cylinders are detected at the same time.

MONITOR DESCRIPTION

The ECM illuminates the MIL and stores a DTC immediately when either one of the following conditions, which could cause catalyst deterioration, is detected (2 trip detection logic).

Within the first 1000 crankshaft revolutions of the engine starting, an excessive misfiring rate (approximately 40 to 60 misfires per 1000 crankshaft revolutions) occurs once.
An excessive misfiring rate (approximately 20 to 50 misfires per 1000 crankshaft revolutions) occurs a total of 4 times.

The ECM flashes the MIL (immediate detection logic) and sets a DTC (2 trip detection logic) when the following condition, which could cause the Three-Way Catalytic Converter (TWC) damage, is detected:

At a normal engine speed, a sufficient amount of misfires to damage the catalyst occurring within 200 crankshaft revolutions is detected 3 times.

MONITOR STRATEGY

Required Sensors/Components (Main)	Crankshaft position sensor and camshaft position sensor
Required Sensors/Components (Related)	Engine coolant temperature, intake air temperature sensors and mass air flow meter
Frequency of Operation	Continuous

TYPICAL ENABLING CONDITIONS

Misfire
Intake air temperature	Higher than -10°C (14°F)
Either of following conditions (a) or (b) met	-
(a) Engine coolant temperature at engine start	Higher than -7°C (19°F)
(b) Engine coolant temperature	Higher than 20°C (68°F)

Monitor Period of Emissions-related Misfire
Duration	1000 crankshaft revolutions x 4

Monitor Period of Catalyst-damaging Misfire (MIL Blinks)
Duration	200 crankshaft revolutions x 3

WIRING DIAGRAM

CONFIRMATION DRIVING PATTERN

Connect the intelligent tester to the DLC3.
Turn the ignition switch to ON.
Turn the intelligent tester on.
Record the DTC(s) and freeze frame data.
Clear the DTCs (even if no DTCs are stored, perform the clear DTC operation).
Using the intelligent tester, switch the ECM from normal mode to check mode (HILUX_TGN26 RM000000PDL0L0X.html).
Read the misfire counts of each cylinder (cylinder No. 1 to No. 4) with the engine idling. If any misfire count is displayed, skip the following confirmation driving pattern.
Drive the vehicle several times with the conditions, such as engine speed and engine load, as shown in Misfire RPM and Misfire Load in the freeze frame data.

HINT:
In order to store misfire DTCs, it is necessary to operate the vehicle for the period of time shown in the table below with the engine speed and engine load the same as Misfire RPM and Misfire Load in the freeze frame data.

Engine Speed
Duration
Idling
8.0 minutes or more
1000
4.5 minutes or more
2000
2.5 minutes or more
3000
1.5 minutes or more
Check whether misfires have occurred by checking DTCs and freeze frame data.
HINT:
Do not turn the ignition switch off until the stored DTCs and freeze frame data have been recorded. When the ECM returns to normal mode (default), the stored DTCs, freeze frame data and other data will be cleared.
Record the DTCs, freeze frame data and misfire counts.
Turn the ignition switch off and wait for at least 30 seconds.
Clear the DTCs (even if no DTCs are stored, perform the clear DTC operation).

INSPECTION PROCEDURE

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 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 misfiring still cannot be reproduced even though the conditions stored in the ECM as freeze frame data have been reproduced, one of the following factors may be a cause of the problem:

The fuel level is low.
Improper fuel is being used.
The spark plugs are dirty.

After finishing repairs, check that no misfires occur in each cylinder (cylinder No. 1, No. 2, No. 3 and No. 4).
Be sure to confirm that no misfiring cylinder DTCs are stored again by conducting the confirmation driving pattern after the repairs.
When one of Short FT #1 or Long FT #1 in the freeze frame data is outside the range of +/-15%, the air-fuel ratio may be rich (-15% or less) or lean (+15% or more).
When Coolant Temp in the freeze frame data is below 75°C (167°F), the misfires may have occurred only while warming up the engine.
An extremely imbalanced drive wheel which causes body vibration may cause misfire DTCs to be stored.

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

Connect the intelligent tester to the DLC3.

Turn the ignition switch to ON.

Turn the intelligent tester on.

Enter the following menus: Powertrain / Engine and ECT / DTC.

Read the DTCs.

Result
Result
Proceed to
P0300, P0301, P0302, P0303 and/or P0304 is output
A
P0300, P0301, P0302, P0303 and/or P0304 and other DTCs are output
B
HINT:
If any DTCs other than P0300, P0301, P0302, P0303 and P0304 are output, troubleshoot those DTCs first.

Result
Result	Proceed to
P0300, P0301, P0302, P0303 and/or P0304 is output	A
P0300, P0301, P0302, P0303 and/or P0304 and other DTCs are output	B

GO TO DTC CHART (HILUX_TGN26 RM0000032SF041X.html)

A

2.CHECK PCV HOSE CONNECTIONS

Check the PCV hose connections (HILUX_TGN26 RM000001I6600NX.html).
OK:
PCV hose is connected correctly and is not damaged.

REPAIR OR REPLACE PCV HOSE (HILUX_TGN26 RM00000142800ZX.html)

OK

3.READ VALUE USING INTELLIGENT TESTER (MISFIRE RPM AND MISFIRE LOAD)

Connect the intelligent tester to the DLC3.

Turn the ignition switch to ON.

Turn the intelligent tester on.

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

Read and note the Misfire RPM and Misfire Load values.
HINT:
The Misfire RPM and Misfire Load values indicate the vehicle conditions under which misfire occurred.

NEXT

4.READ VALUE USING INTELLIGENT TESTER (MISFIRE COUNT)

Connect the intelligent tester to the DLC3.

Turn the ignition switch to ON.

Turn the intelligent tester on.

Clear the DTCs (HILUX_TGN26 RM000000PDK130X.html).

Enter the following menus: Powertrain / Engine and ECT / Data List / All Data / Cylinder #1 Misfire Count, #2, #3 and #4.

Allow the engine to idle.

Read the values for Cylinder #1 Misfire Count to Cylinder #4 Misfire Count displayed on the intelligent tester. If no misfire counts occur in any cylinders, perform the following procedures:
1. Check Cylinder #1 Misfire Count to Cylinder #4 Misfire Count.
2. If misfire counts are still not displayed, perform procedures "A" and "B", and then check the misfire counts again.
  Procedure A: Drive the vehicle while matching the vehicle conditions to the Misfire RPM and Misfire Load values noted in the "Read Value Using Intelligent Tester (Misfire RPM and Misfire Load)" procedure above.
  Procedure B: Read Cylinder #1 Misfire Count to Cylinder #4 Misfire Count or the DTCs output on the intelligent tester.
  
  Result
  Result
  Proceed to
  Most misfires occur in only 1 or 2 cylinders
  A
  3 cylinders or more have equal misfire counts
  B
  HINT:
  1. 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.
  2. If the freeze frame data's record of the engine coolant temperature is below 75°C (167°F), misfire may be detected only when the engine is cold.
  3. If the freeze frame data's record of the Engine Run Time is less than 120 seconds, misfire may be detected immediately after the engine is started.

Result
Result	Proceed to
Most misfires occur in only 1 or 2 cylinders	A
3 cylinders or more have equal misfire counts	B

Go to step 16

A

5.INSPECT SPARK PLUG

Inspect the spark plug of the misfiring cylinder (HILUX_TGN26 RM000000SM604YX_02_0002.html).

REPLACE SPARK PLUG (HILUX_TGN26 RM000000SK7015X.html)

OK

6.CHECK FOR SPARK (SPARK TEST)

Perform a spark test (HILUX_TGN26 RM000000SM604YX_02_0001.html).
HINT:
If the result of the spark test is normal, proceed to the next step.

NEXT

7.CHECK CYLINDER COMPRESSION PRESSURE

Measure the cylinder compression pressure of the misfiring cylinder (HILUX_TGN26 RM000000YN1017X_01_0009.html).

CHECK ENGINE TO DETERMINE CAUSE OF LOW COMPRESSION

OK

8.CHECK FUEL INJECTOR ASSEMBLY (POWER SOURCE)

Disconnect the fuel injector connector.

Turn the ignition switch to ON.

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

Standard Voltage:

Cylinder	Tester Connection	Switch Condition	Specified Condition
No. 1	C65-1 - Body ground	Ignition switch ON	11 to 14 V
No. 2	C2-1 - Body ground	Ignition switch ON	11 to 14 V
No. 3	C66-1 - Body ground	Ignition switch ON	11 to 14 V
No. 4	C4-1 - Body ground	Ignition switch ON	11 to 14 V

Text in Illustration
*a	Front view of wire harness connector (to Fuel Injector Assembly)

GO TO FUEL INJECTOR CIRCUIT (HILUX_TGN26 RM00000330203TX.html)

OK

9.CHECK HARNESS AND CONNECTOR (FUEL INJECTOR - ECM)

Disconnect the fuel injector connector.

Disconnect the ECM connector.

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

Standard Resistance:

Cylinder	Tester Connection	Condition	Specified Condition
No. 1	C65-2 - Body ground	Always	10 kΩ or higher
No. 1	C65-2 - C76-6 (#10)	Always	Below 1 Ω
No. 2	C2-2 - Body ground	Always	10 kΩ or higher
No. 2	C2-2 - C76-5 (#20)	Always	Below 1 Ω
No. 3	C66-2 - Body ground	Always	10 kΩ or higher
No. 3	C66-2 - C76-2 (#30)	Always	Below 1 Ω
No. 4	C4-2 - Body ground	Always	10 kΩ or higher
No. 4	C4-2 - C76-1 (#40)	Always	Below 1 Ω

REPAIR OR REPLACE HARNESS OR CONNECTOR

OK

10.CHECK FUEL INJECTOR ASSEMBLY OF MISFIRING CYLINDER

Check the fuel injector injection [whether fuel volume is high or low, and whether injection pattern is poor] (HILUX_TGN26 RM000000WQQ076X.html).

REPLACE FUEL INJECTOR ASSEMBLY (HILUX_TGN26 RM000000YLB01MX.html)

OK

11.CHECK AIR INDUCTION SYSTEM

Check the air induction system for vacuum leakage.
OK:
No leakage in air induction system.

REPAIR OR REPLACE AIR INDUCTION SYSTEM

OK

12.CHECK FUEL PRESSURE

Check the fuel pressure (HILUX_TGN26 RM000000YL704TX.html).

Go to step 32

OK

13.READ VALUE USING INTELLIGENT TESTER (COOLANT TEMP)

Connect the intelligent tester to the DLC3.

Turn the ignition switch to ON.

Turn the intelligent tester on.

Enter the following menus: Powertrain / Engine and ECT / Data List / All Data / Coolant Temp.

Read Coolant Temp twice, when the engine is both cold and warmed up.
Standard:
With cold engine: Same as ambient air temperature.
With warm engine: Between 75°C and 100°C (167°F and 212°F).

REPLACE ENGINE COOLANT TEMPERATURE SENSOR (HILUX_TGN26 RM000000VWA01WX.html)

OK

14.READ VALUE USING INTELLIGENT TESTER (MAF)

Connect the intelligent tester to the DLC3.

Turn the ignition switch to ON.

Turn the intelligent tester on.

Enter the following menus: Powertrain / Engine and ECT / Data List / All Data / MAF and Coolant Temp.

Allow the engine to idle until Coolant Temp reaches 75°C (167°F) or higher.

Read MAF with the engine speed at 2500 rpm.
Standard:
Between 4 gm/s and 15 gm/s (shift lever: N; A/C: Off).

Go to step 27

OK

15.CHECK VALVE TIMING

Remove the cylinder head cover.

Turn the crankshaft to align the timing marks of the crankshaft.

Align the groove of the crankshaft pulley with the "0" position.

Confirm whether the timing marks of the camshaft pulley and cylinder head cover are facing each other.
HINT:
If the timing marks are not as shown, turn the crankshaft one revolution clockwise.
OK:
The timing marks of the camshaft pulley and the cylinder head cover face each other when the groove of the crankshaft pulley is in the "0" position.
Text in Illustration
*1
Timing Mark

Go to step 27

ADJUST VALVE TIMING (HILUX_TGN26 RM00000125B03XX.html)

16.CHECK AIR INDUCTION SYSTEM

Check the air induction system for vacuum leakage.
OK:
No leakage in air induction system.

REPAIR OR REPLACE AIR INDUCTION SYSTEM

OK

17.CHECK FUEL PRESSURE

Check the fuel pressure (HILUX_TGN26 RM000000YL704TX.html).

Go to step 32

OK

18.READ VALUE USING INTELLIGENT TESTER (COOLANT TEMP)

Connect the intelligent tester to the DLC3.

Turn the ignition switch to ON.

Turn the intelligent tester on.

Enter the following menus: Powertrain / Engine and ECT / Data List / All Data / Coolant Temp.

Read Coolant Temp twice, when the engine is both cold and warmed up.
Standard:
With cold engine: Same as ambient air temperature.
With warm engine: Between 75°C and 100°C (167°F and 212°F).

REPLACE ENGINE COOLANT TEMPERATURE SENSOR (HILUX_TGN26 RM000000VWA01WX.html)

OK

19.READ VALUE USING INTELLIGENT TESTER (MAF)

Connect the intelligent tester to the DLC3.

Turn the ignition switch to ON.

Turn the intelligent tester on.

Enter the following menus: Powertrain / Engine and ECT / Data List / All Data / MAF and Coolant Temp.

Allow the engine to idle until Coolant Temp reaches 75°C (167°F) or higher.

Read MAF with the engine speed at 2500 rpm.
Standard:
Between 4 gm/s and 15 gm/s (shift lever: N; A/C: Off).

Go to step 27

OK

20.CHECK VALVE TIMING

Remove the cylinder head cover.

Turn the crankshaft to align the timing marks of the crankshaft.

Align the groove of the crankshaft pulley with the "0" position.

Confirm whether the timing marks of the camshaft pulley and cylinder head cover are facing each other.
HINT:
If the timing marks are not as shown, turn the crankshaft one revolution clockwise.
OK:
The timing marks of the camshaft pulley and the cylinder head cover face each other when the groove of the crankshaft pulley is in the "0" position.
Text in Illustration
*1
Timing Mark

ADJUST VALVE TIMING (HILUX_TGN26 RM00000125B03XX.html)

OK

21.INSPECT SPARK PLUG

Inspect the spark plug of the misfiring cylinder (HILUX_TGN26 RM000000SM604YX_02_0002.html).

REPLACE SPARK PLUG (HILUX_TGN26 RM000000SK7015X.html)

OK

22.CHECK FOR SPARK (SPARK TEST)

Perform a spark test (HILUX_TGN26 RM000000SM604YX_02_0001.html).
HINT:
If the result of the spark test is normal, proceed to the next step.

NEXT

23.CHECK CYLINDER COMPRESSION PRESSURE

Measure the cylinder compression pressure of the misfiring cylinder (HILUX_TGN26 RM000000YN1017X_01_0009.html).

CHECK ENGINE TO DETERMINE CAUSE OF LOW COMPRESSION

OK

24.CHECK FUEL INJECTOR ASSEMBLY (POWER SOURCE)

Disconnect the fuel injector connector.

Turn the ignition switch to ON.

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

Standard Voltage:

Cylinder	Tester Connection	Switch Condition	Specified Condition
No. 1	C65-1 - Body ground	Ignition switch ON	11 to 14 V
No. 2	C2-1 - Body ground	Ignition switch ON	11 to 14 V
No. 3	C66-1 - Body ground	Ignition switch ON	11 to 14 V
No. 4	C4-1 - Body ground	Ignition switch ON	11 to 14 V

Text in Illustration
*a	Front view of wire harness connector (to Fuel Injector Assembly)

GO TO FUEL INJECTOR CIRCUIT (HILUX_TGN26 RM00000330203TX.html)

OK

25.CHECK HARNESS AND CONNECTOR (FUEL INJECTOR - ECM)

Disconnect the fuel injector connector.

Disconnect the ECM connector.

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

Standard Resistance:

Cylinder	Tester Connection	Condition	Specified Condition
No. 1	C65-2 - Body ground	Always	10 kΩ or higher
No. 1	C65-2 - C76-6 (#10)	Always	Below 1 Ω
No. 2	C2-2 - Body ground	Always	10 kΩ or higher
No. 2	C2-2 - C76-5 (#20)	Always	Below 1 Ω
No. 3	C66-2 - Body ground	Always	10 kΩ or higher
No. 3	C66-2 - C76-2 (#30)	Always	Below 1 Ω
No. 4	C4-2 - Body ground	Always	10 kΩ or higher
No. 4	C4-2 - C76-1 (#40)	Always	Below 1 Ω

REPAIR OR REPLACE HARNESS OR CONNECTOR

OK

26.CHECK FUEL INJECTOR ASSEMBLY OF MISFIRING CYLINDER

Check the fuel injector injection [whether fuel volume is high or low, and whether injection pattern is poor] (HILUX_TGN26 RM000000WQQ076X.html).

REPLACE FUEL INJECTOR ASSEMBLY (HILUX_TGN26 RM000000YLB01MX.html)

OK

27.CHECK HARNESS AND CONNECTOR

Check the connection and terminal contact pressure of connectors and wire harnesses between the mass air flow meter and ECM (HILUX_TGN26 RM000004QR6001X.html).
HINT:
Repair any problems.

NEXT

28.CHECK WHETHER DTC OUTPUT RECURS

Connect the intelligent tester to the DLC3.

Turn the ignition switch to ON.

Turn the intelligent tester on.

Clear the DTCs (HILUX_TGN26 RM000000PDK130X.html).

Turn the ignition switch off and wait for at least 30 seconds.

Turn the ignition switch to ON and turn the intelligent tester on.

Start the engine and warm it up.

Drive the vehicle in accordance with the driving pattern described in Confirmation Driving Pattern.

Enter the following menus: Powertrain / Engine and ECT / Utility / All Readiness.

Input the DTC: P0300, P0301, P0302, P0303 or P0304.

Check the DTC judgment result.

Result
Result
Proceed to
ABNORMAL
(P0300, P0301, P0302, P0303 or P0304 is output)
A
NORMAL
(No DTC is output)
B

END

A

29.CHECK HARNESS AND CONNECTOR (MASS AIR FLOW METER - ECM)

Disconnect the mass air flow meter connector.

Disconnect the ECM connector.

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

Standard Resistance:

Tester Connection
Condition
Specified Condition
C36-3 (VG) - C76-28 (VG)
Always
Below 1 Ω
C36-2 (E2G) - C76-30 (E2G)
Always
Below 1 Ω
C36-3 (VG) or C76-28 (VG) - Body ground
Always
10 kΩ or higher

REPAIR OR REPLACE HARNESS OR CONNECTOR

OK

30.REPLACE MASS AIR FLOW METER

Replace the mass air flow meter (HILUX_TGN26 RM000000VW602CX.html).
HINT:
If the results of the inspections performed in steps 14 and 19 indicated no problem, proceed to the next step without replacing the mass air flow meter.

NEXT

31.CONFIRM WHETHER MALFUNCTION HAS BEEN SUCCESSFULLY REPAIRED

Connect the intelligent tester to the DLC3.

Turn the ignition switch to ON.

Turn the intelligent tester on.

Clear the DTCs (HILUX_TGN26 RM000000PDK130X.html).

Turn the ignition switch off and wait for at least 30 seconds.

Turn the ignition switch to ON and turn the intelligent tester on.

Start the engine and warm it up.

Drive the vehicle in accordance with the driving pattern described in Confirmation Driving Pattern.

Enter the following menus: Powertrain / Engine and ECT / Utility / All Readiness.

Input the DTC: P0300, P0301, P0302, P0303 or P0304.

Check the DTC judgment result.

Result
Result
Proceed to
NORMAL
(No DTC is output)
A
ABNORMAL
(P0300, P0301, P0302, P0303 or P0304 is output)
B

REPLACE ECM (HILUX_TGN26 RM000000VW202TX.html)

END

32.CHECK FUEL LINE

Check the fuel lines for leaks or blockage.

REPAIR OR REPLACE FUEL LINE

REPLACE FUEL PUMP (HILUX_TGN26 RM000004PZ300BX.html)

Engine Speed	Duration
Idling	8.0 minutes or more
1000	4.5 minutes or more
2000	2.5 minutes or more
3000	1.5 minutes or more

Result	Proceed to
ABNORMAL (P0300, P0301, P0302, P0303 or P0304 is output)	A
NORMAL (No DTC is output)	B