P0300

2GR-FE ENGINE CONTROL: SFI SYSTEM: P0300-P0306: Random / Multiple Cylinder Misfire Detected

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

DESCRIPTION





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When the engine misfires, high concentrations of hydrocarbons (HC) 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 count. 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 VVT sensor and the crankshaft position sensor. The VVT 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 when the crankshaft rotation speed variations exceed predetermined thresholds.

If the misfire count exceeds the threshold level and could cause emission deterioration, the ECM illuminates the MIL and sets a DTC.





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

MONITOR DESCRIPTION





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

* Within the first 1000 crankshaft revolutions of the engine starting, an excessive misfiring rate (approximately 20 to 50 misfires per 1000 crankshaft revolutions) occurs once.

* After the first 1000 crankshaft revolutions, an excessive misfiring rate (approximately 20 to 60 misfires per 1000 crankshaft revolutions) occurs 4 times in sequential crankshaft revolutions.

* The ECM flashes the MIL and sets a DTC when either one of the following conditions, which could cause the three-way catalytic converter damage, is detected (2 trip detection logic).

* In every 200 crankshaft revolutions at a high engine speed, the threshold misfiring percentage is recorded once.

* In every 200 crankshaft revolutions at a normal engine speed, the threshold misfiring percentage is recorded 3 times.

MONITOR STRATEGY





TYPICAL ENABLING CONDITIONS

Misfire

Misfire:

Monitor Period of Emission-Related-Misfire

Monitor Period of Emission-Related-Misfire:

Monitor Period of Catalyst-Damage-Misfire (MIL Blinks)

Monitor Period of Catalyst-Damage-Misfire (MIL Blinks):

TYPICAL MALFUNCTION THRESHOLDS

Monitor Period of Emission-Related-Misfire

Monitor Period of Emission-Related-Misfire:

Monitor Period of Catalyst-Damage-Misfire (MIL Blinks)

Monitor Period of Catalyst-Damage-Misfire (MIL Blinks):

MONITOR RESULT

Refer to Checking Monitor Status Mode 6 Data.

WIRING DIAGRAM









CONFIRMATION DRIVING PATTERN

1. Connect the Techstream to the DLC3.

2. Turn the ignition switch to ON.

3. Turn the Techstream on.

4. Record the DTC(s) and freeze frame data.

5. Using the Techstream, switch the ECM from normal mode to check mode Check Mode Procedure.

6. Read the misfire counts of each cylinder (Cylinder #1 (to #6) Misfire Count) with the engine idling. If any misfire count is displayed, skip the following confirmation driving pattern.

7. 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, using the Misfire RPM and Misfire Load in the Data List.





8. Check whether misfires have occurred by checking DTCs and freeze frame data.

HINT
Do not turn the ignition switch off until the stored 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 will be cleared.

9. Record the DTC(s), freeze frame data and misfire counts.

10. 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 Techstream. The ECM records vehicle and driving condition information as freeze frame data the moment a DTC is stored. When troubleshooting, freeze frame data can be helpful in determining whether the vehicle was running or stopped, whether the engine was warmed up or not, whether the air fuel ratio was lean or rich, as well as other data recorded at the time of a malfunction.
- If the 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 misfire still cannot be reproduced even though the conditions stored in the ECM as freeze frame data have been reproduced, one of the following factors is considered to be a possible cause of the problem:
(1) There was insufficient fuel volume in the tank.
(2) Improper fuel is used.
(3) The spark plugs have been contaminated.
- After finishing repairs, check the misfire counts of the cylinders (Cylinder #1 Misfire Count to Cylinder #6 Misfire Count).
- Be sure to confirm that no misfiring cylinder DTCs are set again by conducting the confirmation driving pattern after finishing repairs.
- For 6 cylinder engines, the ECM intentionally does not set the specific misfiring cylinder DTCs at high engine speed. If misfires occur only in high engine speed areas, only DTC P0300 is set.
In the event of DTC P0300 being present, perform the following operations:
(1) Clear the DTC DTC Check / Clear.
(2) Start the engine and conduct the confirmation driving pattern.
(3) Read the misfiring rates of each cylinder or DTC(s) using the Techstream.
(4) Repair the cylinder(s) that has a high misfiring rate or is indicated by the DTC.
(5) After finishing repairs, conduct the confirmation driving pattern again, in order to verify that DTC P0300 is not set.
- When one of Short FT #1, Long FT #1, Short FT #2 or Long FT #2 in the freeze frame data is outside the range of +/-20%, 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 less than 75°C (167°F), the misfires have occurred only while the engine is being warmed up.
- An extremely imbalanced drive wheel which causes body vibration may cause misfire DTCs detection.

PROCEDURE

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

(a) Connect the Techstream to the DLC3.

(b) Turn the ignition switch to ON.

(c) Turn the Techstream on.

(d) Enter the following menus: Powertrain / Engine / Trouble Codes.

(e) Read the DTCs.

Result:





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

B -- GO TO DTC CHART Engine Control System - SFI System
A -- Continue to next step.

2. READ VALUE USING TECHSTREAM (MISFIRE RPM AND MISFIRE LOAD)

(a) Connect the Techstream to the DLC3.

(b) Turn the ignition switch to ON.

(c) Turn the Techstream on.

(d) Enter the following menus: Powertrain / Engine / Data List / Misfire RPM and Misfire Load.

(e) 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 -- Continue to next step.

3. CHECK PCV HOSE (HOSE CONNECTIONS)

(a) Check the PCV hose connections Testing and Inspection.

OK:

PCV hose is connected correctly and is not damaged.

NG -- REPAIR OR REPLACE PCV HOSE
OK -- Continue to next step.

4. READ VALUE USING TECHSTREAM (CATALYST OT MF F/C)

(a) Connect the Techstream to the DLC3.

(b) Turn the ignition switch to ON.

(c) Turn the Techstream on.

(d) Enter the following menus: Powertrain / Engine / Data List / Catalyst OT MF F/C.

(e) Read the value displayed on the Techstream.

Result:





B -- READ VALUE USING TECHSTREAM (CYLINDER #1 (TO #6) MISFIRE COUNT)
A -- Continue to next step.

5. PERFORM ACTIVE TEST USING TECHSTREAM

(a) Connect the Techstream to the DLC3.

(b) Turn the ignition switch to ON.

(c) Turn the Techstream on.

(d) Enter the following menus: Powertrain / Engine / Active Test / Prohibit the Catalyst OT Misfire prevent F/C.

(e) Perform the Active Test.

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

NEXT -- Continue to next step.

6. READ VALUE USING TECHSTREAM (CYLINDER #1 (TO #6) MISFIRE COUNT)

(a) Connect the Techstream to the DLC3.

(b) Turn the ignition switch to ON.

(c) Turn the Techstream on (Step "A").

(d) Enter the following menus: Powertrain / Engine / Data List / Cylinder #1 (to #6) Misfire Count (Step "B").

(e) Read each value for Cylinder #1 (to #6) Misfire Count displayed on the Techstream. If no misfire counts occur in any cylinders, perform the following procedure:

(1) Start the engine and let it idle.

(2) Move the shift lever to D.

(3) Check the Cylinder #1 (to #6) Misfire Count.

(4) If misfire counts are still not displayed, perform steps "A" and "B".

(f) Drive the vehicle while satisfying the Misfire RPM and Misfire Load values noted in the "Read Value Using Techstream (Misfire RPM and Misfire Load)" procedure above.

(g) Read Cylinder #1 (to #6) Misfire Count or the DTCs displayed on the Techstream.

Result:





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 Coolant Temp value of the freeze frame data is below 75°C (167°F), the misfire may be detected only when the engine is cold.
- If Engine Run Time value of the freeze frame data is below 120 seconds, the misfire may be detected immediately after the engine is started.

B -- CHECK INTAKE SYSTEM
A -- Continue to next step.

7. CHECK SPARK PLUG

(a) Remove the ignition coil assembly and the spark plug of the misfiring cylinder.





(b) Measure the spark plug electrode gap.

Maximum gap:

1.4 mm (0.0551 in.)

(c) Check the electrode for carbon deposits.

Recommended Spark Plug

Recommended Spark Plug:

NOTICE:
If the electrode gap is larger than the maximum, replace the spark plug. Do not adjust the electrode gap.

(d) Reinstall the ignition coil assembly and the spark plug.

NG -- REPLACE SPARK PLUG Removal
OK -- Continue to next step.

8. CHECK FOR SPARK AND IGNITION (SPARK TEST)

(a) Perform a spark test.

CAUTION:
During the test, disconnect all fuel injector assembly connectors.

NOTICE:
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 assembly.

(3) Disconnect the 6 fuel injector assembly 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 assembly connectors.

(7) Reinstall the ignition coil assembly.

NG -- CHANGE TO KNOWN GOOD SPARK PLUG AND CHECK SPARK OF MISFIRING CYLINDER
OK -- Continue to next step.

9. CHECK CYLINDER COMPRESSION PRESSURE OF MISFIRING CYLINDER

(a) Measure the cylinder compression pressure of the misfiring cylinder Engine.

NG -- CHECK ENGINE TO DETERMINE CAUSE OF LOW COMPRESSION
OK -- Continue to next step.

10. CHECK FUEL INJECTOR ASSEMBLY (POWER SOURCE)

(a) Disconnect the fuel injector assembly connectors.





(b) Turn the ignition switch to ON.

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

Standard Voltage:





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(d) Reconnect the fuel injector assembly connectors.

NG -- CHECK FUEL INJECTOR CIRCUIT
OK -- Continue to next step.

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

(a) Disconnect the fuel injector assembly connectors.

(b) Disconnect the ECM connector.

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

Standard Resistance (Check for Short):





Standard Resistance (Check for Open):





(d) Reconnect the fuel injector assembly connectors.

(e) Reconnect the ECM connector.

NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR (FUEL INJECTOR ASSEMBLY - ECM)
OK -- Continue to next step.

12. INSPECT ECM TERMINAL OF MISFIRING CYLINDER (#10, #20, #30, #40, #50 AND/OR #60 VOLTAGE)

(a) Disconnect the ECM connector.





(b) Turn the ignition switch to ON.

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

Standard Voltage:





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(d) Reconnect the ECM connector.

NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR (ECM - BODY GROUND)
OK -- Continue to next step.

13. CHECK FUEL INJECTOR ASSEMBLY OF MISFIRING CYLINDER

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

NG -- REPLACE FUEL INJECTOR ASSEMBLY Removal
OK -- Continue to next step.

14. INSPECT INTAKE SYSTEM FOR VACUUM LEAK

(a) Inspect the intake system for vacuum leaks Testing and Inspection.

OK:

No leaks in intake system.

NG -- REPAIR OR REPLACE INTAKE SYSTEM
OK -- Continue to next step.

15. CHECK FUEL PRESSURE

(a) Check the fuel pressure Testing and Inspection.

NG -- CHECK FUEL LINE
OK -- Continue to next step.

16. READ VALUE USING TECHSTREAM (COOLANT TEMP)

(a) Connect the Techstream to the DLC3.

(b) Turn the ignition switch to ON.

(c) Turn the Techstream on.

(d) Enter the following menus: Powertrain / Engine / Data List / Coolant Temp.

(e) Read the Coolant Temp twice, when the engine is both cold and warmed up.

Standard:

With cold engine
Same as ambient temperature.

With warm engine
Between 75°C and 95°C (167°F and 203°F).

NG -- REPLACE ENGINE COOLANT TEMPERATURE SENSOR Removal
OK -- Continue to next step.

17. INSPECT MASS AIR FLOW METER SUB-ASSEMBLY

HINT
Inspect the mass air flow meter sub-assembly On-Vehicle Inspection.

NG -- REPLACE MASS AIR FLOW METER SUB-ASSEMBLY Removal
OK -- Continue to next step.

18. CHECK VALVE TIMING

HINT
Check the valve timing Reassembly.

NG -- ADJUST VALVE TIMING Reassembly

OK -- REPLACE ECM Removal

19. CHECK INTAKE SYSTEM

(a) Check the intake system for vacuum leaks Testing and Inspection.

OK:

No leaks in intake system.

NG -- REPAIR OR REPLACE INTAKE SYSTEM
OK -- Continue to next step.

20. CHECK FUEL PRESSURE

(a) Check the fuel pressure Testing and Inspection.

NG -- CHECK FUEL LINE
OK -- Continue to next step.

21. READ VALUE USING TECHSTREAM (COOLANT TEMP)

(a) Connect the Techstream to the DLC3.

(b) Turn the ignition switch to ON.

(c) Turn the Techstream on.

(d) Enter the following menus: Powertrain / Engine / Data List / Coolant Temp.

(e) Read the 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).

NG -- REPLACE ENGINE COOLANT TEMPERATURE SENSOR Removal
OK -- Continue to next step.

22. INSPECT MASS AIR FLOW METER SUB-ASSEMBLY

HINT
Inspect the mass air flow meter sub-assembly On-Vehicle Inspection.

NG -- REPLACE MASS AIR FLOW METER SUB-ASSEMBLY Removal
OK -- Continue to next step.

23. CHECK VALVE TIMING

HINT
Check the valve timing Reassembly.

NG -- ADJUST VALVE TIMING Reassembly
OK -- Continue to next step.

24. CHECK SPARK PLUG

(a) Remove the ignition coil assembly and the spark plug of the misfiring cylinder.





(b) Measure the spark plug electrode gap.

Maximum gap:

1.4 mm (0.0551 in.)

(c) Check the electrode for carbon deposits.

Recommended Spark Plug

Recommended Spark Plug:

NOTICE:
If the electrode gap is larger than the maximum, replace the spark plug. Do not adjust the electrode gap.

(d) Reinstall the ignition coil assembly and the spark plug.

NG -- REPLACE SPARK PLUG Removal
OK -- Continue to next step.

25. CHECK FOR SPARK AND IGNITION (SPARK TEST)

(a) Perform a spark test.

CAUTION:
During the test, disconnect all fuel injector assembly connectors.

NOTICE:
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 assembly.

(3) Disconnect the 6 fuel injector assembly 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 assembly connectors.

(7) Reinstall the ignition coil assembly.

NG -- CHANGE TO KNOWN GOOD SPARK PLUG AND CHECK SPARK OF MISFIRING CYLINDER
OK -- Continue to next step.

26. CHECK CYLINDER COMPRESSION PRESSURE OF MISFIRING CYLINDER

(a) Measure the cylinder compression pressure of the misfiring cylinder Engine.

NG -- CHECK ENGINE TO DETERMINE CAUSE OF LOW COMPRESSION
OK -- Continue to next step.

27. CHECK FUEL INJECTOR ASSEMBLY (POWER SOURCE)

(a) Disconnect the fuel injector assembly connectors.





(b) Turn the ignition switch to ON.

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

Standard Voltage:





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(d) Reconnect the fuel injector assembly connectors.

NG -- CHECK FUEL INJECTOR CIRCUIT
OK -- Continue to next step.

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

(a) Disconnect the fuel injector assembly connectors.

(b) Disconnect the ECM connector.

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

Standard Resistance (Check for Open):





Standard Resistance (Check for Short):





(d) Reconnect the fuel injector assembly connectors.

(e) Reconnect the ECM connector.

NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR (FUEL INJECTOR ASSEMBLY - ECM)
OK -- Continue to next step.

29. INSPECT ECM TERMINAL OF MISFIRING CYLINDER (#10, #20, #30, #40, #50 AND/OR #60 VOLTAGE)

(a) Disconnect the ECM connector.





(b) Turn the ignition switch to ON.

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

Standard Voltage:





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Text in Illustration:

(d) Reconnect the ECM connector.

NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR (ECM - BODY GROUND)
OK -- Continue to next step.

30. CHECK FUEL INJECTOR ASSEMBLY OF MISFIRING CYLINDER

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

NG -- REPLACE FUEL INJECTOR ASSEMBLY Removal

OK -- REPLACE ECM Removal

31. CHANGE TO KNOWN GOOD SPARK PLUG AND CHECK SPARK OF MISFIRING CYLINDER

(a) Change the installed spark plug to a known good spark plug.

(b) Perform a spark test.

CAUTION:
During the test, disconnect all fuel injector assembly connectors.

NOTICE:
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 assembly.

(3) Disconnect the 6 fuel injector assembly 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 assembly connectors.

(7) Reinstall the ignition coil assembly.

NG -- CHANGE TO KNOWN GOOD IGNITION COIL AND CHECK SPARK OF MISFIRING CYLINDER

OK -- REPLACE SPARK PLUG Removal

32. CHANGE TO KNOWN GOOD IGNITION COIL AND CHECK SPARK OF MISFIRING CYLINDER

(a) Change the installed ignition coil assembly to a known good ignition coil assembly.

(b) Perform a spark test.

CAUTION:
During the test, disconnect all fuel injector assembly connectors.

NOTICE:
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 assembly.

(3) Disconnect the 6 fuel injector assembly 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 assembly connectors.

(7) Reinstall the ignition coil assembly.

NG -- REPLACE ECM Removal

OK -- REPLACE IGNITION COIL ASSEMBLY Removal

33. CHECK FUEL LINE

(a) Check the fuel lines for leaks or blockage.

NG -- REPAIR OR REPLACE FUEL LINE

OK -- REPLACE FUEL SUCTION WITH PUMP AND GAGE TUBE ASSEMBLY Removal