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: Procedure

1. Connect Techstream to the DLC3.
2. Turn the engine switch on (IG).
3. Turn the tester on.
4. Enter the following menus: Powertrain / Engine / Trouble Codes.
5. Read DTCs.

   HINT: 

   Write down the DTCs.

   Result

   Display (DTC Output)	Proceed to
   P0300, P0301, P0302, P0303, P0304, P0305 and/or P0306	A
   P0300, P0301, P0302, P0303, P0304, P0305 and/or P0306 and other DTCs	B

   HINT: 

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

B → See step   31 

A: Go to next step 

OK

PCV hose is correctly connected and is not damaged.

NG → REPAIR OR REPLACE PCV HOSE 

OK: Go to next step 

1. Connect Techstream to the DLC3.
2. Turn the engine switch on (IG) and turn the tester on.
3. Enter the following menus: Powertrain / Engine / Data List / Misfire / Misfire RPM and Misfire Load.
4. 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: Go to next step 

1. Connect Techstream to the DLC3.
2. Turn the engine switch on (IG) and turn the tester on.
3. Enter the following menus: Powertrain / Engine / Data List / Catalyst OT MF F/C.
4. Read the value displayed on the tester.

   Result

   Data List	Tester Display	Proceed to
   Catalyst OT MF F/C	Avail	A
   	Not Avl	B

B → See step   6 

A: Go to next step 

1. Connect Techstream to the DLC3.
2. Turn the engine switch on (IG) and turn the tester on.
3. Enter the following menus: Powertrain / Engine / Active Test / Prohibit the Catalyst OT Misfire prevent F/C.
4. Perform the Active Test.
   NOTE:

   When performing the Active Test, make sure the vehicle is stopped and either idling or being revved within 3000 rpm.

NEXT: Go to next step 

1. Enter the following menus: Powertrain / Engine / Data List / Misfire / Cylinder #1 Misfire Count, #2, #3, #4, #5 and #6
2. Read each value for Cylinder #1 Misfire Count to #6 displayed on the tester. If no misfire counts occur in any cylinders, perform the following procedures:
   1. Start the engine and let it idle.
   2. Move the shift lever to the D position.
   3. Check the Cylinder #1 Misfire Count to #6.
   4. If misfire counts are still not displayed, perform steps (c) and (d).
3. Drive the vehicle with the Misfire RPM and Misfire Load noted in the "Read value Using Techstream (Misfire RPM and Misfire Load)" procedures above (Step c).
4. Read the Cylinder #1 Misfire Count to #6 or DTCs displayed on the tester (Step d).

   Result

   Misfire Count	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'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.

B → See step   18 

A: Go to next step 

Fig 1: Identifying Spark Plug Electrode Gap

Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

1. Remove the ignition coil and the spark plug of the misfiring cylinder.
2. Measure the spark plug electrode gap.

   Maximum Electrode Gap for Used Spark Plug

   1.4 mm (0.0551 in.)

   If the gap is grater than the maximum, replace the spark plug.

   Electrode Gap for New Spark Plug

   1.0 to 1.1 mm (0.0394 to 0.0433 in.)

3. Check the electrode for carbon deposits.
   RECOMMENDED SPARK PLUG:
   
   

   Manufacturer	Product
   DENSO	FK20HBR11

   NOTE:

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

4. Reinstall the ignition coil and the spark plug.

NG → REPLACE SPARK PLUG 

OK: Go to next step 

1. Disconnect the injector connectors to prevent the engine from starting.
   WARNING:

   Always disconnect all injector connectors.

   NOTE:

   Do not crank the engine for more than 2 seconds.

2. Remove the ignition coil from the cylinder head.
3. Install the spark plug onto the ignition coil.
4. Attach the spark plug assembly to the cylinder head.
5. Crank the engine for less than 2 seconds and check the spark.

   OK

   Sparks jump across electrode gap.

6. Install the ignition coil.
7. Reconnect the injector connectors.

NG → See step   29 

OK: Go to next step 

1. Measure the cylinder compression pressure of the misfiring cylinder . Refer to ON-VEHICLE INSPECTION - Step 9 .

NG → CHECK ENGINE TO DETERMINE CAUSE OF LOW COMPRESSION 

OK: Go to next step 

1. Disconnect the E5, E3 and E6 connectors.
2. Disconnect the E26 injector driver (EDU) connector.
3. Measure the resistance according to the value(s) in the table below.

   Standard resistance (Check for open)

   Tester Connection	Specified Condition
   #10 (E3-15) - #10 (E26-3)	Below 1 Ω
   #20 (E5-17) - #20 (E26-2)	Below 1 Ω
   #30 (E3-14) - #30 (E26-1)	Below 1 Ω
   #40 (E5-16) - #40 (E26-12)	Below 1 Ω
   #50 (E3-13) - #50 (E26-11)	Below 1 Ω
   #60 (E5-15) - #60 (E26-10)	Below 1 Ω
   INJF (E6-26) - INJF (E26-9)	Below 1 Ω

   Standard resistance (Check for short)

   Tester Connection	Specified Condition
   #10 (E3-15) or #10 (E26-3) - Body ground	10 kΩ or higher
   #20 (E5-17) or #20 (E26-2) - Body ground	10 kΩ or higher
   #30 (E3-14) or #30 (E26-1) - Body ground	10 kΩ or higher
   #40 (E5-16) or #40 (E26-12) - Body ground	10 kΩ or higher
   #50 (E3-13) or #50 (E26-11) - Body ground	10 kΩ or higher
   #60 (E5-15) or #60 (E26-10) - Body ground	10 kΩ or higher
   INJF (E6-26) or INJF (E26-9) - Body ground	10 kΩ or higher

4. Reconnect the ECM connector.
5. Reconnect the injector driver (EDU) connector.

NG → REPAIR OR REPLACE HARNESS OR CONNECTOR 

OK: Go to next step 

1. Disconnect the H1 and I1 connectors.
2. Measure the resistance according to the value(s) in the table below.

   Standard resistance

   Tester Connection	Condition	Specified Condition
   IJ1+ (H1-2) - IJ1- (H1-5)	20°C (68°F)	2.01 to 2.31 Ω
   IJ2+ (I1-3) - IJ2- (I1-6)	20°C (68°F)	2.01 to 2.31 Ω
   IJ3+ (H1-3) - IJ3- (H1-6)	20°C (68°F)	2.01 to 2.31 Ω
   IJ4+ (I1-1) - IJ4- (I1-4)	20°C (68°F)	2.01 to 2.31 Ω
   IJ5+ (H1-1) - IJ5- (H1-4)	20°C (68°F)	2.01 to 2.31 Ω
   IJ6+ (I1-2) - IJ6- (I1-5)	20°C (68°F)	2.01 to 2.31 Ω

3. Reconnect the injector driver (EDU) connector.

NG → REPAIR OR REPLACE HARNESS OR CONNECTOR 

OK: Go to next step 

1. Check the injector resistance . Refer to INSPECTION .
2. Check the injector injection (whether fuel volume is high or low, and whether injection pattern is poor).

NG → See step   32 

OK: Go to next step 

1. Check the air induction system for vacuum leakage.

   OK

   No leakage from air induction system.

NG → REPAIR OR REPLACE AIR INDUCTION SYSTEM 

OK: Go to next step 

NG → ADJUST VALVE TIMING 

OK: Go to next step 

1. Check the fuel pressure for low pressure side . Refer to ON-VEHICLE INSPECTION - Step 2 .
2. Check the fuel pressure for high pressure side . Refer to ON-VEHICLE INSPECTION - Step 3 .

NG → CHECK AND REPLACE FUEL SYSTEM 

OK: Go to next step 

NG → See step   33 

OK: Go to next step 

NG → See step   34 

OK → See step   35 

1. Check the air induction system for vacuum leakage.

   OK

   No leakage from air induction system.

NG → REPAIR OR REPLACE AIR INDUCTION SYSTEM 

OK: Go to next step 

NG → ADJUST VALVE TIMING 

OK: Go to next step 

1. Check the fuel pressure for low pressure side . Refer to ON-VEHICLE INSPECTION - Step 2 .
2. Check the fuel pressure for high pressure side . Refer to ON-VEHICLE INSPECTION - Step 3 .

NG → CHECK AND REPLACE FUEL SYSTEM 

OK: Go to next step 

NG → See step   33 

OK: Go to next step 

NG → See step   34 

OK: Go to next step 

Fig 2: Identifying Spark Plug Electrode Gap

Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

1. Remove the ignition coil and the spark plug of the misfiring cylinder.
2. Measure the spark plug electrode gap.

   Maximum Electrode Gap for Used Spark Plug

   1.4 mm (0.0551 in.)

   If the gap is grater than the maximum, replace the spark plug.

   Electrode Gap for New Spark Plug

   1.0 to 1.1 mm (0.0394 to 0.0433 in.)

3. Check the electrode for carbon deposits.
   RECOMMENDED SPARK PLUG:
   
   

   Manufacturer	Product
   DENSO	FK20HBR11

   NOTE:

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

4. Reinstall the ignition coil and spark plug.

NG → REPLACE SPARK PLUG 

OK: Go to next step 

1. Disconnect the injector connectors to prevent the engine from starting.
   WARNING:

   Always disconnect all injector connectors.

   NOTE:

   Do not crank the engine for more than 2 seconds.

2. Remove the ignition coil from the cylinder head.
3. Install the spark plug onto the ignition coil.
4. Attach the spark plug assembly to the cylinder head.
5. Crank the engine for less than 2 seconds and check the spark.

   OK

   Sparks jump across electrode gap.

6. Install the ignition coil.
7. Reconnect the injector connectors.

NG → See step   29 

OK: Go to next step 

1. Measure the cylinder compression pressure of the misfiring cylinder . Refer to ON-VEHICLE INSPECTION - Step 9 .

NG → REPAIR OR REPLACE HARNESS OR CONNECTOR 

OK: Go to next step 

1. Disconnect the E5, E3 and E6 connectors.
2. Disconnect the E26 injector driver (EDU) connector.
3. Measure the resistance according to the value(s) in the table below.

   Standard resistance (Check for open)

   Tester Connection	Specified Condition
   #10 (E3-15) - #10 (E26-3)	Below 1 Ω
   #20 (E5-17) - #20 (E26-2)	Below 1 Ω
   #30 (E3-14) - #30 (E26-1)	Below 1 Ω
   #40 (E5-16) - #40 (E26-12)	Below 1 Ω
   #50 (E3-13) - #50 (E26-11)	Below 1 Ω
   #60 (E5-15) - #60 (E26-10)	Below 1 Ω
   INJF (E6-26) - INJF (E26-9)	Below 1 Ω

   Standard resistance (Check for short)

   Tester Connection	Specified Condition
   #10 (E3-15) or #10 (E26-3) - Body ground	10 kΩ or higher
   #20 (E5-17) or #20 (E26-2) - Body ground	10 kΩ or higher
   #30 (E3-14) or #30 (E26-1) - Body ground	10 kΩ or higher
   #40 (E5-16) or #40 (E26-12) - Body ground	10 kΩ or higher
   #50 (E3-13) or #50 (E26-11) - Body ground	10 kΩ or higher
   #60 (E5-15) or #60 (E26-10) - Body ground	10 kΩ or higher
   INJF (E6-26) or INJF (E26-9) - Body ground	10 kΩ or higher

4. Reconnect the ECM connector.
5. Reconnect the injector driver (EDU) connector.

NG → REPAIR OR REPLACE HARNESS OR CONNECTOR 

OK: Go to next step 

1. Disconnect the H1 and I1 connectors.
2. Measure the resistance according to the value(s) in the table below.

   Standard resistance

   Tester Connection	Condition	Specified Condition
   IJ1+ (H1-2) - IJ1- (H1-5)	20°C (68°F)	2.01 to 2.31 Ω
   IJ2+ (I1-3) - IJ2- (I1-6)	20°C (68°F)	2.01 to 2.31 Ω
   IJ3+ (H1-3) - IJ3- (H1-6)	20°C (68°F)	2.01 to 2.31 Ω
   IJ4+ (I1-1) - IJ4- (I1-4)	20°C (68°F)	2.01 to 2.31 Ω
   IJ5+ (H1-1) - IJ5- (H1-4)	20°C (68°F)	2.01 to 2.31 Ω
   IJ6+ (I1-2) - IJ6- (I1-5)	20°C (68°F)	2.01 to 2.31 Ω

3. Reconnect the injector driver (EDU) connector.

NG → REPAIR OR REPLACE HARNESS OR CONNECTOR 

OK: Go to next step 

1. Check the injector resistance . Refer to INSPECTION .
2. Check the injector injection (whether fuel volume is high or low, and whether injection pattern is poor).

NG → See step   32 

OK → See step   35 

1. Change the installed spark plug to a spark plug that functions normally.
2. Perform a spark test.
   WARNING:

   Always disconnect all injector connectors.

   NOTE:

   Do not crank the engine for more than 2 seconds.

   1. Remove the ignition coil from the cylinder head.
   2. Install the spark plug to the ignition coil and connect the ignition coil connector.
   3. Disconnect the injector connector.
   4. Ground the spark plug.
   5. Check if sparks occur while the engine is being cranked.

      OK

      Sparks jump across electrode gap.

   6. Reconnect the injector connector.
   7. Reinstall the ignition coil.

NG → See step   30 

OK → REPLACE SPARK PLUG 

1. Change the installed ignition coil to a known good ignition coil.
2. Perform a spark test.
   WARNING:

   During the test, disconnect all fuel injector connectors.

   NOTE:

   Do not crank the engine for more than 2 seconds.

   1. Remove the ignition coil assembly from the cylinder head.
   2. Install the spark plug onto the ignition coil.
   3. Disconnect the 6 fuel injector connectors.
   4. Touch the spark plug to the cylinder head.
   5. Crank the engine for less than 2 seconds and check for spark.

      OK

      Spark jumps across electrode gap.

   6. Reconnect the 6 fuel injector connectors.
   7. Reinstall the ignition coil.

NG → See step   35 

OK → REPLACE IGNITION COIL