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

When the engine misfires, high concentrations of hydrocarbons enter the exhaust gas. Extremely high hydrocarbon concentration levels can cause increases in exhaust emission levels. High concentrations of hydrocarbons can also cause increases in the three way catalytic converter temperature, which may cause damage to the three way catalytic converter. 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 reaches the point of thermal degradation, the ECM blinks the MIL. 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 crankshaft position sensor is used to measure variations in the crankshaft rotation speed. Misfires are counted when the crankshaft rotation speed variations exceed predetermined thresholds.
If the misfire rate exceeds the threshold level and could cause emission deterioration, the ECM illuminates the MIL and stores a DTC.

DTC No.	DTC Detection Condition	Trouble Area
P0300	Simultaneous misfiring of several cylinders is detected (2-trip detection logic).	Open or short in engine wire harness Connector connections 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 connection 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): High temperature misfire occurs in the Three-way Catalytic Converter (TWC) (MIL blinks). Catalyst deterioration misfire occurs (MIL illuminates).

When DTCs for misfiring cylinders are randomly 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.

WIRING DIAGRAM

Refer to DTC P0201 (HILUX_TGN26 RM0000033OD00KX_02.html).

CONFIRMATION DRIVING PATTERN

Connect the intelligent tester to the DLC3.
Turn the ignition switch to ON.
Turn the tester on.
Record the DTC(s) and freeze frame data.
Clear the DTCs (HILUX_TGN26 RM000000PDK12LX.html).
Start the engine and warm it up (until the engine coolant temperature is 75°C (167°F) or more) with all the accessories switched off.
Using the tester, switch the ECM from normal mode to check mode (HILUX_TGN26 RM000000PDL0LAX.html).
Drive the vehicle at 60 km/h (37 mph) or more for 20 minutes or more.
CAUTION:
When performing the confirmation driving pattern, obey all speed limits and traffic laws.
HINT:
1. This step is performed to complete ethyl alcohol concentration leaning.
2. If DTC P0300, P0301, P0302, P0303 or P0304 is output when any of the following conditions is met, it is necessary to complete ethyl alcohol concentration learning to meet preconditions.
Read the misfire counts of each cylinder, Cylinder #1 Misfire Count to Cylinder #4 Misfire Count, 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, shown in Misfire RPM and Misfire Load in the Data List.

HINT:
In order to store misfire DTCs, it is necessary to operate the vehicle for the period of time shown in the table below. Confirm the Misfire RPM and Misfire Load in the Data List.

Engine Speed
Duration
Idling
8 minutes or more
1000
4 minutes 30 seconds or more
1500
2 minutes 30 seconds or more
2500
1 minute 30 seconds or more
Check whether misfires have occurred by checking DTCs and freeze frame data.
HINT:
Do not turn the ignition switch off until the output DTC(s) and freeze frame data have been recorded. When the ECM returns to normal mode (default), the stored DTC(s), freeze frame data and other data are cleared.
Record the DTC(s), freeze frame data and misfire counts.
Turn the ignition switch off and wait for at least 5 seconds.

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 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 reproduced, one of the following factors can be considered to be a possible cause of the problem:

The fuel level is low.
Improper fuel was used.
The spark plugs are dirty.
The problem is complex and involves multiple factors.

After finishing repairs, check that no misfire occurs in any cylinder (Cylinder #1, #2, #3 and #4).
Be sure to confirm that no misfiring cylinder DTCs are stored again by conducting the confirmation driving pattern after the repairs.
When either Short FT #1 or Long FT #1 values in the freeze frame data are not within 20% of the central value, 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 below 75°C (167°F), the misfires occurred only while warming up the engine.

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 tester on.

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

Read the DTCs.

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

GO TO DTC CHART (HILUX_TGN26 RM000000PDF0H4X.html)

A

2.CHECK PCV HOSE CONNECTIONS

Check the PCV hose connections.
OK:
PCV hose is correctly connected and is not damaged.

REPAIR OR REPLACE PCV HOSE

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 and turn the tester on.

Enter the following menus: Powertrain / Engine and ECT / Data List / 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 the 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 tester on.

Enter the following menus: Powertrain / Engine and ECT / Data List / Cylinder #1 (to #4) Misfire Count.

Drive the vehicle at the engine speed and engine load noted in the "Read Value Using Intelligent Tester (Misfire RPM and Misfire Load)" procedure above.

Read Cylinder #1 (to #4) Misfire Count or the DTCs displayed on the tester.

Result
Misfire Count or DTC Result	Proceed to
Most misfires occur in only 1 or 2 cylinders, or misfire DTCs for only 1 or 2 cylinders are output	A
3 cylinders or more have equal misfire counts, or misfire DTCs for 3 or more cylinders are output	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 engine coolant temperature 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.

Go to step 16

A

5.INSPECT SPARK PLUG

Check the spark plug of the misfiring cylinder (HILUX_TGN26 RM000000SM604ZX_02_0002.html).

REPLACE SPARK PLUG (HILUX_TGN26 RM000000SK7016X_01_0014.html)

OK

6.CHECK FOR SPARK AND IGNITION

Perform a spark test (HILUX_TGN26 RM000000SM604ZX_02_0001.html).

Go to step 32

OK

7.CHECK CYLINDER COMPRESSION PRESSURE

Measure the cylinder compression pressure of the misfiring cylinder (HILUX_TGN26 RM000000YN1018X_01_0009.html).

CHECK ENGINE TO DETERMINE CAUSE OF LOW COMPRESSION

OK

8.CHECK FUEL INJECTOR ASSEMBLY (POWER SOURCE)

Disconnect the fuel injector assembly connector.

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

Standard Voltage:

Tester Connection	Switch Condition	Specified Condition
C65-1 - Body ground	Ignition switch ON	11 to 14 V
C2-1 - Body ground	Ignition switch ON	11 to 14 V
C66-1 - Body ground	Ignition switch ON	11 to 14 V
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)

Reconnect the fuel injector assembly connector.

GO TO FUEL INJECTOR CIRCUIT (HILUX_TGN26 RM000000ZRM0H1X.html)

OK

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

Disconnect the fuel injector assembly connector.

Disconnect the ECM connector.

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

Standard Resistance (Check for Open):

Tester Connection	Condition	Specified Condition
C65-2 - C98-6 (#10)	Always	Below 1 Ω
C2-2 - C98-7 (#20)	Always	Below 1 Ω
C66-2 - C98-8 (#30)	Always	Below 1 Ω
C4-2 - C98-9 (#40)	Always	Below 1 Ω

Standard Resistance (Check for Short):

Tester Connection	Condition	Specified Condition
C65-2 or C98-6 (#10) - Body ground	Always	10 kΩ or higher
C2-2 or C98-7 (#20) - Body ground	Always	10 kΩ or higher
C66-2 or C98-8 (#30) - Body ground	Always	10 kΩ or higher
C4-2 or C98-9 (#40) - Body ground	Always	10 kΩ or higher

Reconnect the fuel injector assembly connector.

Reconnect the ECM connector.

REPAIR OR REPLACE HARNESS OR CONNECTOR

OK

10.CHECK FUEL INJECTOR OF MISFIRING CYLINDER

Check the fuel injector injection (whether fuel volume is high or low, and whether injection pattern is poor) (HILUX_TGN26 RM000000YL901AX.html).

REPLACE FUEL INJECTOR ASSEMBLY (HILUX_TGN26 RM000000YLB01KX.html)

OK

11.CHECK AIR INDUCTION SYSTEM

Check the air induction system for vacuum leakage (HILUX_TGN26 RM000001A3W025X.html).
OK:
No leakage from air induction system.

REPAIR OR REPLACE AIR INDUCTION SYSTEM

OK

12.CHECK FUEL PRESSURE

Check the fuel pressure (HILUX_TGN26 RM000000YL704QX.html).

Go to step 34

OK

13.READ VALUE USING INTELLIGENT TESTER (COOLANT TEMP)

Connect the intelligent tester to the DLC3.

Turn the ignition switch to ON.

Turn the tester on.

Enter the following menus: Powertrain / Engine and ECT / Data List / 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 95°C (167°F and 203°F).

REPLACE ENGINE COOLANT TEMPERATURE SENSOR (HILUX_TGN26 RM000000VWA01XX.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 3000 rpm.
Standard:
Between 10 gm/s and 11.5 gm/s (shift lever: N; A/C: Off).

Go to step 27

OK

15.CHECK VALVE TIMING

HINT:

There are no marks on the cylinder head to align for the purpose of checking valve timing. Valve timing can only be inspected by aligning the colored plates on the timing chain with the marks on the pulleys. It may be necessary to remove and reinstall the chain to align the timing marks (HILUX_TGN26 RM00000125B041X.html).

ADJUST VALVE TIMING

OK

16.CHECK AIR INDUCTION SYSTEM

Check the air induction system for vacuum leakage (HILUX_TGN26 RM000001A3W025X.html).
OK:
No leakage from air induction system.

REPAIR OR REPLACE AIR INDUCTION SYSTEM

OK

17.CHECK FUEL PRESSURE

Check the fuel pressure (HILUX_TGN26 RM000000YL704QX.html).

Go to step 34

OK

18.READ VALUE USING INTELLIGENT TESTER (COOLANT TEMP)

Connect the intelligent tester to the DLC3.

Turn the ignition switch to ON.

Turn the tester on.

Enter the following menus: Powertrain / Engine and ECT / Data List / 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 95°C (167°F and 203°F).

REPLACE ENGINE COOLANT TEMPERATURE SENSOR (HILUX_TGN26 RM000000VWA01XX.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 3000 rpm.
Standard:
Between 10 gm/s and 11.5 gm/s (shift lever: N; A/C: Off).

Go to step 27

OK

20.CHECK VALVE TIMING

HINT:

ADJUST VALVE TIMING

OK

21.INSPECT SPARK PLUG

Inspect the spark plug of the misfiring cylinder (HILUX_TGN26 RM000000SM604ZX_02_0002.html).

REPLACE SPARK PLUG (HILUX_TGN26 RM000000SK7016X_01_0014.html)

OK

22.CHECK FOR SPARK AND IGNITION

Perform a spark test (HILUX_TGN26 RM000000SM604ZX_02_0001.html).

Go to step 32

OK

23.CHECK CYLINDER COMPRESSION PRESSURE

Measure the cylinder compression pressure of the misfiring cylinder (HILUX_TGN26 RM000000YN1018X_01_0009.html).

CHECK ENGINE TO DETERMINE CAUSE OF LOW COMPRESSION

OK

24.CHECK FUEL INJECTOR ASSEMBLY (POWER SOURCE)

Disconnect the fuel injector assembly connector.

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

Standard Voltage:

Tester Connection	Switch Condition	Specified Condition
C65-1 - Body ground	Ignition switch ON	11 to 14 V
C2-1 - Body ground	Ignition switch ON	11 to 14 V
C66-1 - Body ground	Ignition switch ON	11 to 14 V
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)

Reconnect the fuel injector assembly connector.

GO TO FUEL INJECTOR CIRCUIT (HILUX_TGN26 RM000000ZRM0H1X.html)

OK

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

Disconnect the fuel injector assembly connector.

Disconnect the ECM connector.

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

Standard Resistance (Check for Open):

Tester Connection	Condition	Specified Condition
C65-2 - C98-6 (#10)	Always	Below 1 Ω
C2-2 - C98-7 (#20)	Always	Below 1 Ω
C66-2 - C98-8 (#30)	Always	Below 1 Ω
C4-2 - C98-9 (#40)	Always	Below 1 Ω

Standard Resistance (Check for Short):

Tester Connection	Condition	Specified Condition
C65-2 or C98-6 (#10) - Body ground	Always	10 kΩ or higher
C2-2 or C98-7 (#20) - Body ground	Always	10 kΩ or higher
C66-2 or C98-8 (#30) - Body ground	Always	10 kΩ or higher
C4-2 or C98-9 (#40) - Body ground	Always	10 kΩ or higher

Reconnect the fuel injector assembly connector.

Reconnect the ECM connector.

REPAIR OR REPLACE HARNESS OR CONNECTOR

OK

26.CHECK FUEL INJECTOR OF MISFIRING CYLINDER

Check the fuel injector injection (whether fuel volume is high or low, and whether injection pattern is poor) (HILUX_TGN26 RM000000YL901AX.html).

REPLACE FUEL INJECTOR ASSEMBLY (HILUX_TGN26 RM000000YLB01KX.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 RM000000PDK12LX.html).

Turn the ignition switch off.

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
Display (DTC Output)
Proceed to
ABNORMAL
(P0300, P0301, P0302, P0303 or P0304 output)
A
NORMAL
(No DTC 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 (Check for Open):
Tester Connection
Condition
Specified Condition
C36-3 (VG) - C95-13 (VG)
Always
Below 1 Ω
C36-2 (E2G) - C95-7 (E2G)
Always
Below 1 Ω
Standard Resistance (Check for Short):
Tester Connection
Condition
Specified Condition
C36-3 (VG) or C95-13 (VG) - Body ground
Always
10 kΩ or higher

Reconnect the mass air flow meter connector.

Reconnect the ECM connector.

REPAIR OR REPLACE HARNESS OR CONNECTOR

OK

30.REPLACE MASS AIR FLOW METER

Replace the mass air flow meter (HILUX_TGN26 RM000000VW602DX.html).
HINT:
If the result of the inspection performed in step 14 and 19 indicated no problem, proceed to the next step without replacing the mass air flow meter assembly.

NEXT

31.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 RM000000PDK12LX.html).

Turn the ignition switch off.

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

REPLACE ECM (HILUX_TGN26 RM000000VW2024X.html)

END

32.REPLACE SPARK PLUG WITH NORMAL ONE AND CHECK SPARK OF MISFIRING CYLINDER

Replace the installed spark plug with a spark plug that functions normally.

Perform a spark test.
CAUTION:
During the test, disconnect all the injector connectors.
NOTICE:
Do not crank the engine for more than 2 seconds.
1. Install the spark plug to the ignition coil.
2. Disconnect the 4 fuel injector connectors.
3. Touch the spark plug assembly to the cylinder head.
4. Crank the engine for less than 2 seconds and check for sparks.
  OK:
  Sparks jump across electrode gap.

Go to step 33

REPLACE SPARK PLUG (HILUX_TGN26 RM000000SK7016X_01_0014.html)

33.REPLACE IGNITION COIL WITH NORMAL ONE AND CHECK SPARK OF MISFIRING CYLINDER

Replace the ignition coil with an ignition coil that functions normally.

Perform a spark test.
CAUTION:
During the test, disconnect all the injector connectors.
NOTICE:
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 4 fuel injector connectors.
3. Touch the spark plug assembly to the cylinder head.
4. Crank the engine for less than 2 seconds and check for sparks.
  OK:
  Sparks jump across electrode gap.

REPLACE ECM (HILUX_TGN26 RM000000VW2024X.html)

REPLACE IGNITION COIL (HILUX_TGN26 RM000000SK7016X_01_0004.html)

34.CHECK FUEL LINE

Check the fuel lines for leaks or blockage (HILUX_TGN26 RM000000YL704QX_01_0001.html).
OK:
No leaks or blockage.

REPAIR OR REPLACE FUEL LINE

REPLACE FUEL PUMP (HILUX_TGN26 RM000000YLL055X.html)

Engine Speed	Duration
Idling	8 minutes or more
1000	4 minutes 30 seconds or more
1500	2 minutes 30 seconds or more
2500	1 minute 30 seconds or more

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