DTC P0300-00: Random/Multiple Cylinder Misfire Detected; DTC P0300-27: Random/Multiple Cylinder Misfire Detected (Emission) Signal Rate of Change Above Threshold; DTC P0300-85: Random / Multiple Cylinder Misfire Detected (Over Temperature) Signal Above Allowable Range; DTC P0301-00: Cylinder 1 Misfire Detected; DTC P0302-00: Cylinder 2 Misfire Detected; DTC P0303-00: Cylinder 3 Misfire Detected; DTC P0304-00: Cylinder 4 Misfire Detected [11/2023 - ]: Procedure

1. Read the DTCs.

   Powertrain > Engine > Trouble Codes 

   Result

   Result	Proceed to
   DTC P0300-00, P0300-27, P0300-85, P0301-00, P0302-00, P0303-00 and/or P0304-00 are output	A
   DTC P0300-00, P0300-27, P0300-85, P0301-00, P0302-00, P0303-00 and/or P0304-00 and other DTCs are output	B

   HINT: 

   If any DTCs other than P0300-00, P0300-27, P0300-85, P0301-00, P0302-00, P0303-00 and/or P0304-00 are output, troubleshoot those DTCs first.

Result: 

B 

GO TO DTC CHART. Refer to  DIAGNOSTIC TROUBLE CODE CHART [11/2023 - ] 

Result: 

A 

See step  2

Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

1. Check the PCV hose connections.
2. Check the PCV valve.

   Refer to INSPECTION [10/2022 - ]

   OK

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

   Result

   Proceed to
   OK
   NG

Result: 

NG 

REPAIR OR REPLACE PCV VALVE OR HOSE 

Result: 

OK 

See step  3

1. Read and note the Misfire RPM and Misfire Load values.

   Powertrain > Engine > Data List 

   Tester Display
   Misfire RPM
   Misfire Load

   HINT: 

   The Misfire RPM and Misfire Load values indicate the vehicle conditions under which the misfire occurred.

   Result

   Proceed to
   NEXT

Result: 

NEXT 

See step  4

1. Read the value displayed on the GTS.

   Powertrain > Engine > Data List 

   Tester Display
   Catalyst OT Misfire Fuel Cut

   Result

   Data List	Result	Proceed to
   Catalyst OT Misfire Fuel Cut	Avail	A
   	Not Avi	B

Result: 

B 

See step  7

Result: 

A 

See step  5

1. Using the GTS, confirm the vehicle conditions recorded in the Freeze Frame Data which were present when the DTC was stored.

   Refer to FREEZE FRAME DATA [11/2023 - ]

   Result

   Freeze Frame Data Item	Result	Proceed to
   Catalyst OT Misfire Fuel Cut History	ON	A
   	OFF	B

Result: 

B 

See step  7

Result: 

A 

See step  6

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

   Powertrain > Engine > Data List 

   Tester Display
   Coolant Temperature

2. Read each value for Misfire Count Cylinder #1 to Misfire Count Cylinder #4 and Injection Mode displayed on the GTS while performing the Active Test.

   Powertrain > Engine > Active Test 

   Active Test Display
   Prohibit the Catalyst OT Misfire Prevent Fuel Cut

   Data List Display
   Injection Mode
   Misfire Count Cylinder #1
   Misfire Count Cylinder #2
   Misfire Count Cylinder #3
   Misfire Count Cylinder #4

   Result

   Injection Mode	Misfire Count	Proceed to
   Port	1 or 2 cylinders have misfire counts	A
   	3 cylinders or more have misfire counts
   	There are no misfire counts	B

Result: 

A 

See step  8

Result: 

B 

See step  11

1. Start the engine and warm it up until the engine coolant temperature reaches 80°C (176°F) or higher.

   Powertrain > Engine > Data List 

   Tester Display
   Coolant Temperature

2. According to the display on the GTS, read the Data List with the Active Test "Control the Injection Mode" set to Port. If no misfire counts occur in any cylinders, perform procedure [A] and [B] and then check the misfire counts again.

   Powertrain > Engine > Active Test 

   Active Test Display
   Control the Injection Mode

   Data List Display
   Injection Mode
   Misfire Count Cylinder #1
   Misfire Count Cylinder #2
   Misfire Count Cylinder #3
   Misfire Count Cylinder #4

   1. Drive the vehicle with the Misfire RPM and Misfire Load noted in the "Read Value Using GTS (Misfire RPM and Misfire Load)" procedures above [A].
   2. Read the Injection Mode and Misfire Count Cylinder #1 to Misfire Count Cylinder #4 or DTCs displayed on the GTS [B].

   Result

   Injection Mode	Misfire Count	Proceed to
   Port	1 or 2 cylinders have misfire counts	A
   	3 cylinders or more have misfire counts
   	There are no misfire counts	B

Result: 

B 

See step  11

Result: 

A 

See step  8

1. Start the engine and warm it up until the engine coolant temperature reaches 80°C (176°F) or higher.

   Powertrain > Engine > Data List 

   Tester Display
   Coolant Temperature

2. According to the display on the GTS, read the Data List with the Active Test "Control the Injection Mode" set to Direct. If no misfire counts occur in any cylinders, perform procedure [A] and [B] and then check the misfire counts again.

   Powertrain > Engine > Active Test 

   Active Test Display
   Control the Injection Mode

   Data List Display
   Injection Mode
   Misfire Count Cylinder #1
   Misfire Count Cylinder #2
   Misfire Count Cylinder #3
   Misfire Count Cylinder #4

   1. Drive the vehicle with the Misfire RPM and Misfire Load noted in the "Read Value Using GTS (Misfire RPM and Misfire Load)" procedures above [A].
   2. Read the Injection Mode and Misfire Count Cylinder #1 to Misfire Count Cylinder #4 or DTCs displayed on the GTS [B].

   Result

   Misfire Count		Proceed to
   Port (Result of step 6 or 7)	Direct
   1 or 2 cylinders have misfire counts	1 or 2 cylinders have misfire counts	A
   3 cylinders or more have misfire counts	3 cylinders or more have misfire counts	B
   1 or 2 cylinders have misfire counts	There are no misfire counts	C
   3 cylinders or more have misfire counts	There are no misfire counts	D

   HINT: 

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

   Refer to INITIALIZATION [10/2022 - ]

Result: 

A 

See step  14

Result: 

B 

See step  17

Result: 

C 

REPLACE PORT FUEL INJECTOR ASSEMBLY (MISFIRING CYLINDER). Refer to  REMOVAL [11/2023 - ] 

Result: 

D 

See step  9

1. Check the fuel pressure (for low pressure side).

   Refer to PROCEDURE - Step 2

   HINT: 

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

   Refer to INITIALIZATION [10/2022 - ]

   Result

   Proceed to
   OK
   NG

Result: 

OK 

REPLACE PORT FUEL INJECTOR ASSEMBLY (MISFIRING CYLINDER). Refer to  REMOVAL [11/2023 - ] 

Result: 

NG 

See step  10

1. Check the fuel lines for leaks or blockage.

   HINT: 

   Perform "Inspection After Repair" after replacing the fuel pump (for low pressure side).

   Refer to INITIALIZATION [10/2022 - ]

   Result

   Proceed to
   OK
   NG

Result: 

OK 

GO TO FUEL PUMP CONTROL CIRCUIT. Refer to  Fuel Pump Control Circuit [10/2022 - ] 

Result: 

NG 

REPAIR OR REPLACE FUEL SYSTEM 

1. Start the engine and warm it up until the engine coolant temperature reaches 80°C (176°F) or higher.

   Powertrain > Engine > Data List 

   Tester Display
   Coolant Temperature

2. According to the display on the GTS, read the Data List with the Active Test "Control the Injection Mode" set to Direct. If no misfire counts occur in any cylinders, perform procedure [A] and [B] and then check the misfire counts again.

   Powertrain > Engine > Active Test 

   Active Test Display
   Control the Injection Mode

   Data List Display
   Injection Mode
   Misfire Count Cylinder #1
   Misfire Count Cylinder #2
   Misfire Count Cylinder #3
   Misfire Count Cylinder #4

   1. Drive the vehicle with the Misfire RPM and Misfire Load noted in the "Read Value Using GTS (Misfire RPM and Misfire Load)" procedures above [A].
   2. Read the Injection Mode and Misfire Count Cylinder #1 to Misfire Count Cylinder #4 or DTCs displayed on the GTS [B].

   Result

   Misfire Count		Proceed to
   Port (Result of step 6 or 7)	Direct
   There are no misfire counts	There are misfire counts	A
   There are no misfire counts	There are no misfire counts	B

   HINT: 

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

   Refer to INITIALIZATION [10/2022 - ]

Result: 

A 

REPLACE DIRECT FUEL INJECTOR ASSEMBLY. Refer to  REMOVAL [11/2023 - ] 

Result: 

B 

See step  12

1. Clear the DTCs.

   Powertrain > Engine > Clear DTCs 

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

   Result

   Proceed to
   NEXT

Result: 

NEXT 

See step  13

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

   Powertrain > Engine > Data List 

   Tester Display
   Coolant Temperature

2. Drive the vehicle with Misfire RPM and Misfire Load.

   Powertrain > Engine > Data List 

   Tester Display
   Injection Mode
   Misfire Count Cylinder #1
   Misfire Count Cylinder #2
   Misfire Count Cylinder #3
   Misfire Count Cylinder #4
   Misfire RPM
   Misfire Load

3. Monitor all of the misfire count values and Injection Mode displayed on the GTS.

   Result

   Misfire Count	Injection Mode	Proceed to
   There are no misfire counts	-	A
   1 or 2 cylinders have misfire counts	Port or Either	B
   3 cylinders or more have misfire counts	Port or Either	C
   There are misfire counts	Direct	D

   HINT: 

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

   Refer to INITIALIZATION [10/2022 - ]

Result: 

A 

CHECK FOR INTERMITTENT PROBLEMS. Refer to  CHECK FOR INTERMITTENT PROBLEMS [10/2022 - ] 

Result: 

C 

See step  17

Result: 

D 

REPLACE DIRECT FUEL INJECTOR ASSEMBLY. Refer to  REMOVAL [11/2023 - ] 

Result: 

B 

See step  14

1. 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 [10/2022 - ]

   Result

   Proceed to
   OK
   NG

Result: 

NG 

REPLACE SPARK PLUG. Refer to  REMOVAL [10/2022 - ] 

Result: 

OK 

See step  15

1. 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 replacing the spark plug or ignition coil assembly.

     Refer to INITIALIZATION [10/2022 - ]

   Result

   Proceed to
   NEXT

Result: 

NEXT 

See step  16

1. Measure the cylinder compression pressure of the misfiring cylinder.

   Refer to PROCEDURE - Step 11

   HINT: 

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

   Refer to INITIALIZATION [10/2022 - ]

   Result

   Proceed to
   OK
   NG

Result: 

OK 

REPLACE ECM. Refer to  REMOVAL [11/2023 - ] 

Result: 

NG 

CHECK ENGINE TO DETERMINE CAUSE OF LOW COMPRESSION 

1. Check the intake system for vacuum leaks.

   Refer to PROCEDURE - Step 1

   OK

   No leaks from intake system.

   HINT: 

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

   Refer to INITIALIZATION [10/2022 - ]

   Result

   Proceed to
   OK
   NG

Result: 

NG 

REPAIR OR REPLACE INTAKE SYSTEM 

Result: 

OK 

See step  18

1. Read the Data List twice, when the engine is both cold and warmed up.

   Powertrain > Engine > Data List 

   Tester Display
   Coolant Temperature

   Standard

   GTS Display	Condition	Specified Condition
   Coolant Temperature	Cold engine	Same as ambient air temperature
   	Warm engine	Between 75 and 115°C (167 and 239°F)

   HINT: 

   Perform "Inspection After Repair" after replacing the engine coolant temperature sensor.

   Refer to INITIALIZATION [10/2022 - ]

   Result

   Proceed to
   OK
   NG

Result: 

NG 

REPLACE ENGINE COOLANT TEMPERATURE SENSOR. Refer to  REMOVAL [11/2023 - ] 

Result: 

OK 

See step  19

1. Start the engine.
2. Allow the engine to idle until Coolant Temperature reaches 75°C (167°F) or higher.

   Powertrain > Engine > Data List 

   Tester Display
   Coolant Temperature

3. Read Mass Air Flow Sensor while maintaining an engine speed of 3000 rpm.

   Powertrain > Engine > Data List 

   Tester Display
   Engine Speed
   Mass Air Flow Sensor

   Standard

   GTS Display	Condition	Specified Condition
   Mass Air Flow Sensor	Engine warmed up Shift position: P A/C: Off Engine Speed: 3000 rpm	Between 5 and 15 gm/sec

   Result

   Proceed to
   OK
   NG

Result: 

NG 

See step  24

Result: 

OK 

See step  20

1. Remove the cylinder head cover sub-assembly.

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

   *a	10.6°	*b	21.91°
   *c	Timing Mark	*d	"0" Timing Mark
   *e	Groove	-	-

2. Turn the crankshaft pulley and align its groove with the "0" timing mark of the timing chain cover.
3. Check that the timing marks of the camshaft timing gear assembly and camshaft timing exhaust gear assembly are at the positions shown in the illustration.

   HINT: 

   If the timing marks are not at the positions shown, turn the crankshaft one revolution clockwise.

   OK

   Timing marks on camshaft timing gear assembly and camshaft timing exhaust gear assembly are at the positions shown in the illustration.

   HINT: 

   If the result is not as specified, check for mechanical malfunctions that may have affected the valve timing, such as a jumped tooth or stretching of the timing chain.

   Result

   Proceed to
   OK
   NG

Result: 

OK 

See step  24

Result: 

NG 

See step  21

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

   HINT: 

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

   Refer to INITIALIZATION [10/2022 - ]

   Result

   Proceed to
   OK
   NG

Result: 

NG 

REPAIR OR REPLACE MALFUNCTIONING PARTS, COMPONENT AND AREA 

Result: 

OK 

See step  22

1. Clear the DTCs.

   Powertrain > Engine > Clear DTCs 

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

   Result

   Proceed to
   NEXT

Result: 

NEXT 

See step  23

1. Drive the vehicle in accordance with the driving pattern described in Confirmation Driving Pattern.
2. Check the DTC judgment result.

   Powertrain > Engine > Utility 

   Tester Display
   All Readiness

3. Input the DTC: P0300-00, P0300-27, P0300-85, P0301-00, P0302-00, P0303-00 or P0304-00.

   Result

   Result	Proceed to
   NORMAL (DTCs are not output)	A
   ABNORMAL (DTC P0300-00, P0300-27, P0300-85, P0301-00, P0302-00, P0303-00 and/or P0304-00 is output)	B

Result: 

A 

CHECK FOR INTERMITTENT PROBLEMS. Refer to  CHECK FOR INTERMITTENT PROBLEMS [10/2022 - ] 

Result: 

B 

See step  24

1. 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 [12/2019 - ]

   HINT: 

   Repair any problems.

   Result

   Proceed to
   NEXT

Result: 

NEXT 

See step  25

1. Clear the DTCs.

   Powertrain > Engine > Clear DTCs 

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

   Result

   Proceed to
   NEXT

Result: 

NEXT 

See step  26

1. Drive the vehicle in accordance with the driving pattern described in Confirmation Driving Pattern.
2. Check the DTC judgment result.

   Powertrain > Engine > Utility 

   Tester Display
   All Readiness

3. Input the DTC: P0300-00, P0300-27, P0300-85, P0301-00, P0302-00, P0303-00 or P0304-00.

   Result

   Result	Proceed to
   NORMAL (DTCs are not output)	A
   ABNORMAL (DTC P0300-00, P0300-27, P0300-85, P0301-00, P0302-00, P0303-00 and/or P0304-00 is output)	B

Result: 

A 

END 

Result: 

B 

See step  27

1. Disconnect the mass air flow meter sub-assembly connector.
2. Disconnect the ECM connector.
3. Measure the resistance according to the value(s) in the table below.

   Standard Resistance

   Tester Connection	Condition	Specified Condition
   C30-3 (VCC) - C88-73 (VCVG)	Always	Below 1 Ω
   C30-1 (FG) - C88-75 (VG)	Always	Below 1 Ω
   C30-2 (E2G) - C88-74 (E2G)	Always	Below 1 Ω
   C30-3 (VCC) or C88-73 (VCVG) - Body ground and other terminals	Always	10 kΩ or higher
   C30-1 (FG) or C88-75 (VG) - Body ground and other terminals	Always	10 kΩ or higher
   C30-2 (E2G) or C88-74 (E2G) - Body ground and other terminals	Always	10 kΩ or higher

   Result

   Proceed to
   OK
   NG

Result: 

NG 

REPAIR OR REPLACE HARNESS OR CONNECTOR 

Result: 

OK 

See step  28

1. Replace the mass air flow meter sub-assembly.

   Refer to REMOVAL [10/2022 - ]

   HINT: 

   • If the results of the inspections performed in step 19 (READ VALUE USING GTS (MASS AIR FLOW SENSOR)) 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 [10/2022 - ]

   Result

   Proceed to
   NEXT

Result: 

NEXT 

See step  29

1. Clear the DTCs.

   Powertrain > Engine > Clear DTCs 

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

   Result

   Proceed to
   NEXT

Result: 

NEXT 

See step  30

1. Drive the vehicle in accordance with the driving pattern described in Confirmation Driving Pattern.
2. Check the DTC judgment result.

   Powertrain > Engine > Utility 

   Tester Display
   All Readiness

3. Input the DTC: P0300-00, P0300-27, P0300-85, P0301-00, P0302-00, P0303-00 or P0304-00.

   Result

   Result	Proceed to
   NORMAL (DTCs are not output)	A
   ABNORMAL (DTC P0300-00, P0300-27, P0300-85, P0301-00, P0302-00, P0303-00 and/or P0304-00 is output)	B

Result: 

A 

END 

Result: 

B 

REPLACE ECM. Refer to  REMOVAL [11/2023 - ]