P0300

2GR-FXE 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

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

The ECM illuminates the MIL and stores 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 after the engine starts, an excessive number of misfires (approximately 10 to 50 misfires per 1000 crankshaft revolutions) occurs once.

- An excessive number of misfires (approximately 10 to 50 misfires per 1000 crankshaft revolutions) occurs a total of 4 times.

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

- At a high engine speed, a sufficient amount of misfires to damage the catalyst occurring within 200 crankshaft revolutions is detected once.

- At a normal engine speed, a sufficient amount of misfires to damage the catalyst occurring within 200 crankshaft revolutions is detected 3 times.

MONITOR STRATEGY





TYPICAL ENABLING CONDITIONS

Misfire





Monitor Period of Emission-Related Misfire





Monitor Period of Catalyst-Damage Misfire (MIL Blinks)





TYPICAL MALFUNCTION THRESHOLDS

Monitor Period of Emission-Related Misfire





Monitor Period of Catalyst-Damage Misfire (MIL Blinks)





MONITOR RESULT

Refer to Checking Monitor Status Mode 6 Data.

WIRING DIAGRAM

Refer to DTC P0102 P0102.

Refer to Fuel Injector Circuit Fuel Injector Circuit.

CONFIRMATION DRIVING PATTERN

1. Connect the Techstream to the DLC3.

2. Turn the power switch on (IG).

3. Turn the Techstream on.

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

5. Clear DTCs (even if no DTCs are stored, perform the clear DTC operation).

6. Put the engine in inspection mode Component Tests and General Diagnostics.

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

8. Drive the vehicle several times with the conditions, such as engine speed and engine load, as shown in Misfire RPM and Misfire Load in the freeze frame data.

HINT
In order to store misfire DTCs, it is necessary to operate the vehicle for the period of time shown in the table below with the engine speed and engine load the same as Misfire RPM and Misfire Load in the freeze frame data.





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

HINT
Do not turn the power switch off until the stored DTCs and freeze frame data have been recorded. When the ECM returns to normal mode (default), the stored DTCs, freeze frame data and other data will be cleared.

10. Record the DTCs, freeze frame data and misfire counts.

11. Turn the power switch off and wait for at least 30 seconds.

12. Clear DTCs (even if no DTCs are stored, perform the clear DTC operation).

INSPECTION PROCEDURE

NOTICE:
Inspect the fuses for circuits related to this system before performing the following 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 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 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 engine, 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 DTCs Reading and Clearing Diagnostic Trouble Codes.
(2) Put the engine in inspection mode Component Tests and General Diagnostics.
(3) Start the engine and conduct the confirmation driving pattern.
(4) Read the misfiring rates of each cylinder or DTC(s) using the Techstream.
(5) Repair the cylinder(s) that has a high misfiring rate or is indicated by the DTC.
(6) 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 power switch on (IG).

(c) Turn the Techstream on.

(d) Enter the following menus: Powertrain / Engine and ECT / 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 SFI System
A -- Continue to next step.

2. CHECK PCV 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.

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

(a) Connect the Techstream to the DLC3.

(b) Turn the power switch on (IG).

(c) Turn the Techstream on.

(d) Enter the following menus: Powertrain / Engine and ECT / 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.

4. READ VALUE USING TECHSTREAM (MISFIRE COUNT)

(a) Connect the Techstream to the DLC3.

(b) Turn the power switch on (IG).

(c) Turn the Techstream on.

(d) Put the engine in inspection mode Component Tests and General Diagnostics.

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

(f) Start the engine and allow the engine to idle.

(g) Read each value for Cylinder #1 (to #6) Misfire Count displayed on the Techstream. If no misfire counts occur in any cylinders, perform steps [A] and [B], and then check the misfire counts again.

(h) Drive the vehicle with the Misfire RPM and Misfire Load noted in the read value using the Techstream (Misfire RPM and Misfire Load) procedures above [A].

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

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 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.

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

5. INSPECT SPARK PLUG

(a) Inspect the spark plug Testing and Inspection.

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

6. CHECK FOR SPARK (SPARK TEST)

(a) Perform a spark test Testing and Inspection.

HINT
If the result of the spark test is normal, proceed to the next step.

NEXT -- Continue to next step.

7. CHECK CYLINDER COMPRESSION PRESSURE

(a) Measure the cylinder compression pressure of the misfiring cylinder On-Vehicle Inspection.

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

8. CHECK TERMINAL VOLTAGE (POWER SOURCE OF FUEL INJECTOR)

(a) Disconnect the ECM connector.

(b) Turn the power switch on (IG).

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

Standard Voltage:





(d) Reconnect the ECM connector.

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

9. 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.

10. INSPECT INTAKE SYSTEM

(a) Check the intake system for vacuum leaks Intake System.

OK:

No leakage in intake system.

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

11. CHECK FUEL PRESSURE

(a) Check the fuel pressure Fuel System.

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

12. READ VALUE USING TECHSTREAM (COOLANT TEMP) P0171

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

13. READ VALUE USING TECHSTREAM (MAF) P0171

NG -- CHECK HARNESS AND CONNECTOR (MASS AIR FLOW METER SUB-ASSEMBLY CONNECTOR CONNECTION)
OK -- Continue to next step.

14. CHECK VALVE TIMING (CHECK FOR LOOSE OR JUMPED TEETH ON TIMING CHAIN) P0011

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

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

(a) Connect the Techstream to the DLC3.

(b) Turn the power switch on (IG).

(c) Turn the Techstream on.

(d) Put the engine in inspection mode Component Tests and General Diagnostics.

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

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

(f) Enter the following menus: Powertrain / Engine and ECT / Active Test / Control the EGR Step Position.

(g) Check the engine idling condition and MAP values 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 Active Test is completed.
- Do not open the EGR valve 30 steps or more during the Active Test.

OK:

MAP and idling condition change in response to EGR step position as follows.

Standard:





HINT
During Active Test, if the idling condition does not change in response to EGR step position, then there is probably a malfunction in EGR valve.

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

NG -- INSPECT EGR VALVE ASSEMBLY

16. INSPECT EGR VALVE ASSEMBLY

(a) Remove the EGR valve assembly Removal.

(b) Check if the EGR valve is stuck open.

OK:

EGR valve is tightly closed.

(c) Reinstall the EGR valve assembly Installation.

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

NG -- REPLACE EGR VALVE ASSEMBLY Removal

17. CHECK INTAKE SYSTEM

(a) Check the intake system for vacuum leaks Intake System.

OK:

No leakage in intake system.

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

18. CHECK FUEL PRESSURE

(a) Check the fuel pressure Fuel System.

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

19. READ VALUE USING TECHSTREAM (COOLANT TEMP) P0171

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

20. READ VALUE USING TECHSTREAM (MAF) P0171

NG -- CHECK HARNESS AND CONNECTOR (MASS AIR FLOW METER SUB-ASSEMBLY CONNECTOR CONNECTION)
OK -- Continue to next step.

21. CHECK VALVE TIMING (CHECK FOR LOOSE OR JUMPED TEETH ON TIMING CHAIN) P0011

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

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

(a) Connect the Techstream to the DLC3.

(b) Turn the power switch on (IG).

(c) Turn the Techstream on.

(d) Put the engine in inspection mode Component Tests and General Diagnostics.

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

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

(f) Enter the following menus: Powertrain / Engine and ECT / Active Test / Control the EGR Step Position.

(g) Check the engine idling condition and MAP values 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 Active Test is completed.
- Do not open the EGR valve 30 steps or more during the Active Test.

OK:

MAP and idling condition change in response to EGR step position as follows.

Standard:





HINT
During Active Test, if the idling condition does not change in response to EGR step position, then there is probably a malfunction in EGR valve.

OK -- INSPECT SPARK PLUG

NG -- INSPECT EGR VALVE ASSEMBLY

23. INSPECT EGR VALVE ASSEMBLY

(a) Remove the EGR valve assembly Removal.

(b) Check if the EGR valve is stuck open.

OK:

EGR valve is tightly closed.

(c) Reinstall the EGR valve assembly Installation.

NG -- REPLACE EGR VALVE ASSEMBLY Removal
OK -- Continue to next step.

24. INSPECT SPARK PLUG

(a) Inspect the spark plug Testing and Inspection.

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

25. CHECK FOR SPARK (SPARK TEST)

(a) Perform a spark test Testing and Inspection.

HINT
If the result of the spark test is normal, proceed to the next step.

NEXT -- Continue to next step.

26. CHECK CYLINDER COMPRESSION PRESSURE

(a) Measure the cylinder compression pressure of the misfiring cylinder On-Vehicle Inspection.

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

27. CHECK TERMINAL VOLTAGE (POWER SOURCE OF FUEL INJECTOR)

(a) Disconnect the ECM connector.

(b) Turn the power switch on (IG).

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

Standard Voltage:





(d) Reconnect the ECM connector.

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

28. 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.

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

(a) Check the connection and terminal contact pressure of connectors and wire harnesses between the mass air flow meter sub-assembly and ECM Electronic Circuit Inspection Procedure.

HINT
Repair any problems.

NEXT -- Continue to next step.

30. CHECK WHETHER DTC OUTPUT RECURS

(a) Connect the Techstream to the DLC3.

(b) Turn the power switch on (IG).

(c) Turn the Techstream on.

(d) Clear the DTCs Reading and Clearing Diagnostic Trouble Codes.

(e) Turn the power switch off and wait for 30 seconds.

(f) Turn the power switch on (IG) and turn the Techstream on.

(g) Put the engine in inspection mode Component Tests and General Diagnostics.

(h) Start the engine and warm it up.

(i) Drive the vehicle in accordance with the driving pattern described in Confirmation Driving Pattern.

(j) Enter the following menus: Powertrain / Engine and ECT / Utility / All Readiness.

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

(l) Check the DTC judgment result.

Result





B -- END
A -- Continue to next step.

31. CHECK HARNESS AND CONNECTOR (MASS AIR FLOW METER SUB-ASSEMBLY - ECM) P0102

NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR (MASS AIR FLOW METER SUB-ASSEMBLY - ECM)
OK -- Continue to next step.

32. REPLACE MASS AIR FLOW METER SUB-ASSEMBLY

(a) Replace the mass air flow meter sub-assembly Removal.

HINT
If the results of the inspections performed in steps 13 and 20 indicated no problem, proceed to the next step without replacing the mass air flow meter sub-assembly.

NEXT -- Continue to next step.

33. CONFIRM WHETHER MALFUNCTION HAS BEEN SUCCESSFULLY REPAIRED

(a) Connect the Techstream to the DLC3.

(b) Turn the power switch on (IG).

(c) Turn the Techstream on.

(d) Clear the DTC Reading and Clearing Diagnostic Trouble Codes.

(e) Turn the power switch off and wait for 30 seconds.

(f) Turn the power switch on (IG) and turn the Techstream on.

(g) Put the engine in inspection mode Component Tests and General Diagnostics.

(h) Start the engine and warm it up.

(i) Drive the vehicle in accordance with the driving pattern described in the Confirmation Driving Pattern.

(j) Enter the following menus: Powertrain / Engine and ECT / Utility / All Readiness.

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

(l) Check the DTC judgment result.

Result





B -- REPLACE ECM Removal

A -- END

34. CHECK FUEL LINE

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

NG -- REPAIR OR REPLACE FUEL LINE

OK -- REPLACE FUEL PUMP Removal