DTC P0300: Random / Multiple Cylinder Misfire Detected; DTC P0301: Cylinder 1 Misfire Detected; DTC P0302: Cylinder 2 Misfire Detected; DTC P0303: Cylinder 3 Misfire Detected; DTC P0304: Cylinder 4 Misfire Detected; DTC P0305: Cylinder 5 Misfire Detected; DTC P0306: Cylinder 6 Misfire Detected [02/2014 - 08/2014]: Procedure

WARNING: This page is about a different car, the 2016 Toyota Highlander, 2015 Toyota Highlander, and 2014 Toyota Highlander. However, it is still accessible from the selected car via links, so may be relevant.

CHECK ANY OTHER DTCS OUTPUT (IN ADDITION TO MISFIRE DTCS)

Connect the Techstream to the DLC3.
Turn the power switch on (IG).
Turn the Techstream on.
Enter the following menus: Powertrain / Engine and ECT / Trouble Codes.

Read the DTCs.

Powertrain > Engine and ECT > Trouble Codes

Result

Result	Proceed to
DTC P0300, P0301, P0302, P0303, P0304, P0305 and/or P0306 are output	A
DTC P0300, P0301, P0302, P0303, P0304, P0305 and/or P0306 and other DTCs are output	B

HINT:

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

Result: 2

GO TO DTC CHART. Refer to DIAGNOSTIC TROUBLE CODE CHART [02/2014 - 08/2014]

Result: 1

See step 2

CHECK PCV HOSE CONNECTIONS

Check the PCV hose connections.

Refer to COMPONENTS [02/2014 - 11/2016]

PCV valve and hose are correctly connected and are not damaged.

Result

Proceed to
OK
NG

Result: 2

REPAIR OR REPLACE PCV HOSE

Result: 1

See step 3

READ VALUE USING TECHSTREAM (MISFIRE RPM AND MISFIRE LOAD)

Connect the Techstream to the DLC3.
Turn the power switch on (IG).
Turn the Techstream on.

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

Powertrain > Engine and ECT > Data List

Tester Display
Misfire RPM
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.

Result

Proceed to
NEXT

Result: 1

See step 4

READ VALUE USING TECHSTREAM (CYLINDER MISFIRE COUNT)

Connect the Techstream to the DLC3.
Turn the power switch on (IG).
Turn the Techstream on.

Put the engine in inspection mode (maintenance mode).

Refer to INSPECTION MODE PROCEDURE [02/2014 - 11/2016]

Powertrain > Hybrid Control > Utility

Tester Display
Inspection Mode

Enter the following menus: Powertrain / Engine and ECT / Data List / Gas Misfire / Cylinder #1 Misfire Count, Cylinder #2 Misfire Count, Cylinder #3 Misfire Count, Cylinder #4 Misfire Count, Cylinder #5 Misfire Count and Cylinder #6 Misfire Count.

Powertrain > Engine and ECT > Data List

Tester Display
Cylinder #1 Misfire Count
Cylinder #2 Misfire Count
Cylinder #3 Misfire Count
Cylinder #4 Misfire Count
Cylinder #5 Misfire Count
Cylinder #6 Misfire Count

Start the engine and allow the engine to idle.
Read each value for Cylinder #1 Misfire Count to Cylinder #6 Misfire Count displayed on the Techstream. If no misfire counts occur in any cylinders, perform procedure [A] and [B] and then check the misfire counts again.
Drive the vehicle with the Misfire RPM and Misfire Load noted in the "Read Value Using Techstream (Misfire RPM And Misfire Load)" procedures above [A].

Read the Cylinder #1 Misfire Count to Cylinder #6 Misfire Count or DTCs displayed on the Techstream [B].

Result

Result	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 record of the engine coolant temperature is less than 75°C (167°F), the misfire may be detected only when the engine is cold.

Result: 2

See step 18

Result: 1

See step 5

INSPECT SPARK PLUG

Inspect the spark plug of the misfiring cylinder.

Refer to PROCEDURE - Step 3

HINT:

Perform "Inspection After Repair" after replacing the spark plug.

Refer to INITIALIZATION [02/2014 - 11/2016]

Result

Proceed to
OK
NG

Result: 2

REPLACE SPARK PLUG. Refer to PROCEDURE - Step 3

Result: 1

See step 6

CHECK FOR SPARKS (SPARK TEST)

Perform a spark test.

Refer to PROCEDURE - Step 1

HINT:

If the result of the spark test is normal, proceed to the next step.
Perform "Inspection After Repair" after repairing or replacing the ignition system.
Refer to INITIALIZATION [02/2014 - 11/2016]

Result

Proceed to
NEXT

Result: 1

See step 7

CHECK CYLINDER COMPRESSION PRESSURE

Measure the cylinder compression pressure of the misfiring cylinder.

Refer to PROCEDURE - Step 10

HINT:

Perform "Inspection After Repair" after repairing or replacing the engine assembly.

Refer to INITIALIZATION [02/2014 - 11/2016]

Result

Proceed to
OK
NG

Result: 2

CHECK ENGINE TO DETERMINE CAUSE OF LOW COMPRESSION

Result: 1

See step 8

CHECK TERMINAL VOLTAGE (#10, #20, #30, #40, #50 AND/OR #60)

Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

*a	Front view of wire harness connector (to ECM)

Disconnect the ECM connector.
Turn the power switch on (IG).

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

Standard Voltage

Tester Connection	Condition	Specified Condition
C1-19 (#10) - C1-57 (E01)	Power switch on (IG)	11 to 14 V
C1-20 (#20) - C1-57 (E01)	Power switch on (IG)	11 to 14 V
C1-53 (#30) - C1-57 (E01)	Power switch on (IG)	11 to 14 V
C1-49 (#40) - C1-57 (E01)	Power switch on (IG)	11 to 14 V
C1-21 (#50) - C1-57 (E01)	Power switch on (IG)	11 to 14 V
C1-52 (#60) - C1-57 (E01)	Power switch on (IG)	11 to 14 V

Result

Proceed to
OK
NG

Result: 2

CHECK FUEL INJECTOR CIRCUIT. Refer to Fuel Injector Circuit [02/2014 - 11/2016]

Result: 1

See step 9

CHECK FUEL INJECTOR ASSEMBLY OF MISFIRING CYLINDER

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

Refer to INSPECTION [02/2014 - 11/2016]

HINT:

Perform "Inspection After Repair" after replacing the fuel injector assembly.

Refer to INITIALIZATION [02/2014 - 11/2016]

Result

Proceed to
OK
NG

Result: 2

REPLACE FUEL INJECTOR ASSEMBLY. Refer to REMOVAL [02/2014 - 11/2016]

Result: 1

See step 10

CHECK INTAKE SYSTEM

Check the intake system for vacuum leaks.

Refer to ON-VEHICLE INSPECTION [02/2014 - 11/2016]

No leaks from intake system.

HINT:

Perform "Inspection After Repair" after repairing or replacing the intake system.

Refer to INITIALIZATION [02/2014 - 11/2016]

Result

Proceed to
OK
NG

Result: 2

REPAIR OR REPLACE INTAKE SYSTEM

Result: 1

See step 11

CHECK FUEL PRESSURE

Check the fuel pressure.

Refer to PROCEDURE - Step 2

Result

Proceed to
OK
NG

Result: 2

See step 36

Result: 1

See step 12

READ VALUE USING TECHSTREAM (COOLANT TEMP)
Refer to PROCEDURE - Step 5

Result

Proceed to

OK

NG

Result: 2

NG

REPLACE ENGINE COOLANT TEMPERATURE SENSOR. Refer to REMOVAL [02/2014 - 11/2016]

Result: 1

OK

See step 13
READ VALUE USING TECHSTREAM (MAF)
Refer to PROCEDURE - Step 6

Result

Proceed to

OK

NG

Result: 2

NG

See step 31

Result: 1

OK

See step 14
CHECK VALVE TIMING
Refer to PROCEDURE - Step 5

Result

Proceed to

OK

NG

Result: 2

NG

See step 17

Result: 1

OK

See step 15

PERFORM ACTIVE TEST USING TECHSTREAM (CONTROL THE EGR STEP POSITION)

Connect the Techstream to the DLC3.
Turn the power switch on (IG).
Turn the Techstream on.

Put the engine in inspection mode (maintenance mode).

Refer to INSPECTION MODE PROCEDURE [02/2014 - 11/2016]

Powertrain > Hybrid Control > Utility

Tester Display
Inspection Mode

Start the engine and warm it up until the engine coolant temperature reaches 75°C (167°F) or higher.
HINT:

The A/C switch and all accessory switches should be off.

Enter the following menus: Powertrain / Engine and ECT / Active Test / Control the EGR Step Position / Primary / MAP and Throttle Idle Position.

Powertrain > Engine and ECT > Active Test

Active Test Display
Control the EGR Step Position

Data List Display
MAP
Throttle Idle Position

Confirm that the Throttle Idle Position is ON and check the MAP value in the Data List while performing the Active Test.

HINT:

Do not leave the EGR valve open for 10 seconds or more during the Active Test.
Be sure to return the EGR valve to step 0 when the Active Test is completed.
Do not open the EGR valve 30 steps or more during the Active Test.

MAP change in response to EGR step position when Throttle Idle Position is ON in Data List.

Standard

-	EGR Step Position (Active Test)
-	0 Steps	0 to 30 Steps
MAP (Data List)	(EGR valve is fully closed)	MAP value is at least +10 kPa (75 mmHg) higher than when EGR valve is fully closed

HINT:

While performing the Active Test, if the increase in the value of MAP is small, the EGR valve assembly may be a malfunctioning.
Even if the EGR valve assembly is malfunctioning, rough idling or an increase in the value of MAP may occur while performing the Active Test. However, the amount that the value of MAP increases will be smaller than normal.

Result

Proceed to
OK
NG

Result: 2

See step 31

Result: 1

See step 16

INSPECT EGR VALVE ASSEMBLY

Remove the EGR valve assembly.
Refer to REMOVAL [02/2014 - 11/2016]

Check if the EGR valve is stuck open.

EGR valve is tightly closed.

HINT:

Perform "Inspection After Repair" after replacing the EGR valve assembly.

Refer to INITIALIZATION [02/2014 - 11/2016]

Result

Proceed to
OK
NG

Result: 1

See step 31

Result: 2

REPLACE EGR VALVE ASSEMBLY. Refer to REMOVAL [02/2014 - 11/2016]

CHECK ENGINE MECHANICAL SYSTEM

Check for mechanical malfunctions that affect the valve timing, such as a jumped tooth or stretching of the timing chain.

Result

Proceed to
OK
NG

Result: 1

See step 31

Result: 2

REPAIR OR REPLACE MALFUNCTIONING PARTS, COMPONENT AND AREA

CHECK INTAKE SYSTEM

Check the intake system for vacuum leaks.

Refer to ON-VEHICLE INSPECTION [02/2014 - 11/2016]

No leaks from intake system.

HINT:

Perform "Inspection After Repair" after repairing or replacing the intake system.

Refer to INITIALIZATION [02/2014 - 11/2016]

Result

Proceed to
OK
NG

Result: 2

REPAIR OR REPLACE INTAKE SYSTEM

Result: 1

See step 19

CHECK FUEL PRESSURE

Check the fuel pressure.

Refer to PROCEDURE - Step 2

Result

Proceed to
OK
NG

Result: 2

See step 36

Result: 1

See step 20

READ VALUE USING TECHSTREAM (COOLANT TEMP)
Refer to PROCEDURE - Step 5

Result

Proceed to

OK

NG

Result: 2

NG

REPLACE ENGINE COOLANT TEMPERATURE SENSOR. Refer to REMOVAL [02/2014 - 11/2016]

Result: 1

OK

See step 21
READ VALUE USING TECHSTREAM (MAF)
Refer to PROCEDURE - Step 6

Result

Proceed to

OK

NG

Result: 2

NG

See step 31

Result: 1

OK

See step 22
CHECK VALVE TIMING
Refer to PROCEDURE - Step 5

Result

Proceed to

OK

NG

Result: 2

NG

See step 30

Result: 1

OK

See step 23

PERFORM ACTIVE TEST USING TECHSTREAM (CONTROL THE EGR STEP POSITION)

Connect the Techstream to the DLC3.
Turn the power switch on (IG).
Turn the Techstream on.

Put the engine in inspection mode (maintenance mode).

Refer to INSPECTION MODE PROCEDURE [02/2014 - 11/2016]

Powertrain > Hybrid Control > Utility

Tester Display
Inspection Mode

Start the engine and warm it up until the engine coolant temperature reaches 75°C (167°F) or higher.
HINT:

The A/C switch and all accessory switches should be off.

Enter the following menus: Powertrain / Engine and ECT / Active Test / Control the EGR Step Position / Primary / MAP and Throttle Idle Position.

Powertrain > Engine and ECT > Active Test

Active Test Display
Control the EGR Step Position

Data List Display
MAP
Throttle Idle Position

Confirm that the Throttle Idle Position is ON and check the MAP value in the Data List while performing the Active Test.

HINT:

Do not leave the EGR valve open for 10 seconds or more during the Active Test.
Be sure to return the EGR valve to step 0 when the Active Test is completed.
Do not open the EGR valve 30 steps or more during the Active Test.

MAP change in response to EGR step position when Throttle Idle Position is ON in Data List.

Standard

-	EGR Step Position (Active Test)
-	0 Steps	0 to 30 Steps
MAP (Data List)	(EGR valve is fully closed)	MAP value is at least +10 kPa (75 mmHg) higher than when EGR valve is fully closed

HINT:

While performing the Active Test, if the increase in the value of MAP is small, the EGR valve assembly may be a malfunctioning.
Even if the EGR valve assembly is malfunctioning, rough idling or an increase in the value of MAP may occur while performing the Active Test. However, the amount that the value of MAP increases will be smaller than normal.

Result

Proceed to
OK
NG

Result: 2

See step 25

Result: 1

See step 24

INSPECT EGR VALVE ASSEMBLY

Remove the EGR valve assembly.
Refer to REMOVAL [02/2014 - 11/2016]

Check if the EGR valve is stuck open.

EGR valve is tightly closed.

HINT:

Perform "Inspection After Repair" after replacing the EGR valve assembly.

Refer to INITIALIZATION [02/2014 - 11/2016]

Result

Proceed to
OK
NG

Result: 2

REPLACE EGR VALVE ASSEMBLY. Refer to REMOVAL [02/2014 - 11/2016]

Result: 1

See step 25

INSPECT SPARK PLUG

Inspect the spark plug of the misfiring cylinder.

Refer to PROCEDURE - Step 1

HINT:

Perform "Inspection After Repair" after replacing the spark plug.

Refer to INITIALIZATION [02/2014 - 11/2016]

Result

Proceed to
OK
NG

Result: 2

REPLACE SPARK PLUG. Refer to PROCEDURE - Step 3

Result: 1

See step 26

CHECK FOR SPARKS (SPARK TEST)

Perform a spark test.

Refer to PROCEDURE - Step 1

HINT:

If the result of the spark test is normal, proceed to the next step.
Perform "Inspection After Repair" after repairing or replacing the ignition system.
Refer to INITIALIZATION [02/2014 - 11/2016]

Result

Proceed to
NEXT

Result: 1

See step 27

CHECK CYLINDER COMPRESSION PRESSURE

Measure the cylinder compression pressure of the misfiring cylinder.

Refer to PROCEDURE - Step 10

HINT:

Perform "Inspection After Repair" after repairing or replacing the engine assembly.

Refer to INITIALIZATION [02/2014 - 11/2016]

Result

Proceed to
OK
NG

Result: 2

CHECK ENGINE TO DETERMINE CAUSE OF LOW COMPRESSION

Result: 1

See step 28

CHECK TERMINAL VOLTAGE (#10, #20, #30, #40, #50 AND/OR #60)

*a	Front view of wire harness connector (to ECM)

Disconnect the ECM connector.
Turn the power switch on (IG).

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

Standard Voltage

Tester Connection	Condition	Specified Condition
C1-19 (#10) - C1-57 (E01)	Power switch on (IG)	11 to 14 V
C1-20 (#20) - C1-57 (E01)	Power switch on (IG)	11 to 14 V
C1-53 (#30) - C1-57 (E01)	Power switch on (IG)	11 to 14 V
C1-49 (#40) - C1-57 (E01)	Power switch on (IG)	11 to 14 V
C1-21 (#50) - C1-57 (E01)	Power switch on (IG)	11 to 14 V
C1-52 (#60) - C1-57 (E01)	Power switch on (IG)	11 to 14 V

Result

Proceed to
OK
NG

Result: 2

CHECK FUEL INJECTOR CIRCUIT. Refer to Fuel Injector Circuit [02/2014 - 11/2016]

Result: 1

See step 29

CHECK FUEL INJECTOR ASSEMBLY OF MISFIRING CYLINDER

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

Refer to INSPECTION [02/2014 - 11/2016]

HINT:

Perform "Inspection After Repair" after replacing the fuel injector assembly.

Refer to INITIALIZATION [02/2014 - 11/2016]

Result

Proceed to
OK
NG

Result: 1

See step 31

Result: 2

REPLACE FUEL INJECTOR ASSEMBLY. Refer to REMOVAL [02/2014 - 11/2016]

CHECK ENGINE MECHANICAL SYSTEM

Check for mechanical malfunctions that affect the valve timing, such as a jumped tooth or stretching of the timing chain.

Result

Proceed to
OK
NG

Result: 2

REPAIR OR REPLACE MALFUNCTIONING PARTS, COMPONENT AND AREA

Result: 1

See step 31

CHECK HARNESS AND CONNECTOR (MASS AIR FLOW METER SUB-ASSEMBLY CONNECTOR CONNECTION)

Check the connection and terminal contact pressure of connectors and wire harnesses between the mass air flow meter sub-assembly and ECM.

Refer to ELECTRONIC CIRCUIT INSPECTION PROCEDURE [02/2014 - ]

HINT:

Repair any problems.

Result

Proceed to
NEXT

Result: 1

See step 32

CHECK WHETHER DTC OUTPUT RECURS (MISFIRE DTCS)

Connect the Techstream to the DLC3.
Turn the power switch on (IG).
Turn the Techstream on.
Clear the DTCs.
Refer to DTC CHECK / CLEAR [02/2014 - 11/2016]

Powertrain > Engine and ECT > Clear DTCs
Turn the power switch off and wait for at least 30 seconds.
Turn the power switch on (IG) and turn the Techstream on.

Put the engine in inspection mode (maintenance mode).

Refer to INSPECTION MODE PROCEDURE [02/2014 - 11/2016]

Powertrain > Hybrid Control > Utility

Tester Display
Inspection Mode

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.

Powertrain > Engine and ECT > Utility

Tester Display
All Readiness

Input the DTC: P0300, P0301, P0302, P0303, P0304, P0305 or P0306.

Check the DTC judgment result.

Result

Result	Proceed to
ABNORMAL (DTC P0300, P0301, P0302, P0303, P0304, P0305 and/or P0306 is output)	A
NORMAL (DTCs are not output)	B

Result: 2

CHECK FOR INTERMITTENT PROBLEMS. Refer to CHECK FOR INTERMITTENT PROBLEMS [02/2014 - 11/2016]

Result: 1

See step 33

CHECK HARNESS AND CONNECTOR (MASS AIR FLOW METER SUB-ASSEMBLY - ECM)
Refer to PROCEDURE - Step 3

Result

Proceed to

OK

NG

Result: 2

NG

REPAIR OR REPLACE HARNESS OR CONNECTOR

Result: 1

OK

See step 34

REPLACE MASS AIR FLOW METER SUB-ASSEMBLY

Replace the mass air flow meter sub-assembly.

Refer to REMOVAL [02/2014 - 11/2016]

HINT:

If the results of the inspections performed in steps 13 and 21 indicated no problem, proceed to the next step without replacing the mass air flow meter sub-assembly.
Perform "Inspection After Repair" after replacing the mass air flow meter sub-assembly.
Refer to INITIALIZATION [02/2014 - 11/2016]

Result

Proceed to
NEXT

Result: 1

See step 35

CONFIRM WHETHER MALFUNCTION HAS BEEN SUCCESSFULLY REPAIRED

Connect the Techstream to the DLC3.
Turn the power switch on (IG).
Turn the Techstream on.
Clear the DTCs.
Refer to DTC CHECK / CLEAR [02/2014 - 11/2016]

Powertrain > Engine and ECT > Clear DTCs
Turn the power switch off and wait for at least 30 seconds.
Turn the power switch on (IG) and turn the Techstream on.

Put the engine in inspection mode (maintenance mode).

Refer to INSPECTION MODE PROCEDURE [02/2014 - 11/2016]

Powertrain > Hybrid Control > Utility

Tester Display
Inspection Mode

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.

Powertrain > Engine and ECT > Utility

Tester Display
All Readiness

Input the DTC: P0300, P0301, P0302, P0303, P0304, P0305 or P0306.

Check the DTC judgment result.

Result

Result	Proceed to
NORMAL (DTCs are not output)	A
ABNORMAL (DTC P0300, P0301, P0302, P0303, P0304, P0305 and/or P0306 is output)	B

Result: 1

END

Result: 2

REPLACE ECM. Refer to REMOVAL [02/2014 - 11/2016]

CHECK FUEL LINE

Check the fuel lines for leaks or blockage.

HINT:

Perform "Inspection After Repair" after replacing the fuel pump.

Refer to INITIALIZATION [02/2014 - 11/2016]

Result

Proceed to
OK
NG

Result: 1

REPLACE FUEL PUMP. Refer to REMOVAL [02/2014 - 11/2016]

Result: 2

REPAIR OR REPLACE FUEL LINE