| DTC Code | DTC Name |
|---|---|
| P0300 | Random / Multiple Cylinder Misfire Detected |
| P0301 | Cylinder 1 Misfire Detected |
| P0302 | Cylinder 2 Misfire Detected |
| P0303 | Cylinder 3 Misfire Detected |
| P0304 | Cylinder 4 Misfire Detected |
| P0305 | Cylinder 5 Misfire Detected |
| 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 an increase in exhaust emission levels. Extremely 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 this increase 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 levels, and could cause emission control system performance deterioration, the ECM illuminates the MIL and stores a DTC.
| DTC No. | Detection Item | DTC Detection Condition | Trouble Area | MIL | Memory |
|---|---|---|---|---|---|
| P0300 | Random / Multiple Cylinder Misfire Detected | Simultaneous misfiring of several cylinders occurs and one of the following conditions is met (2 trip detection logic):
|
|
Comes on/Blinks* (Euro-OBD) / - (Except Euro-OBD) *: The MIL flashes when a catalyst-damaging misfire is detected. |
DTC stored (Euro-OBD) / - (Except Euro-OBD) |
| P0301 | Cylinder 1 Misfire Detected | Misfiring of a specific cylinder occurs and one of the following conditions is met (2 trip detection logic):
|
|
Comes on/Blinks* (Euro-OBD) / - (Except Euro-OBD) *: The MIL flashes when a catalyst-damaging misfire is detected. |
DTC stored (Euro-OBD) / - (Except Euro-OBD) |
| P0302 | Cylinder 2 Misfire Detected | Misfiring of a specific cylinder occurs and one of the following conditions is met (2 trip detection logic):
|
|
Comes on/Blinks* (Euro-OBD) / - (Except Euro-OBD) *: The MIL flashes when a catalyst-damaging misfire is detected. |
DTC stored (Euro-OBD) / - (Except Euro-OBD) |
| P0303 | Cylinder 3 Misfire Detected | Misfiring of a specific cylinder occurs and one of the following conditions is met (2 trip detection logic):
|
|
Comes on/Blinks* (Euro-OBD) / - (Except Euro-OBD) *: The MIL flashes when a catalyst-damaging misfire is detected. |
DTC stored (Euro-OBD) / - (Except Euro-OBD) |
| P0304 | Cylinder 4 Misfire Detected | Misfiring of a specific cylinder occurs and one of the following conditions is met (2 trip detection logic):
|
|
Comes on/Blinks* (Euro-OBD) / - (Except Euro-OBD) *: The MIL flashes when a catalyst-damaging misfire is detected. |
DTC stored (Euro-OBD) / - (Except Euro-OBD) |
| P0305 | Cylinder 5 Misfire Detected | Misfiring of a specific cylinder occurs and one of the following conditions is met (2 trip detection logic):
|
|
Comes on/Blinks* (Euro-OBD) / - (Except Euro-OBD) *: The MIL flashes when a catalyst-damaging misfire is detected. |
DTC stored (Euro-OBD) / - (Except Euro-OBD) |
| P0306 | Cylinder 6 Misfire Detected | Misfiring of a specific cylinder occurs and one of the following conditions is met (2 trip detection logic):
|
|
Comes on/Blinks* (Euro-OBD) / - (Except Euro-OBD) *: The MIL flashes when a catalyst-damaging misfire is detected. |
DTC stored (Euro-OBD) / - (Except Euro-OBD) |
When DTCs for misfiring cylinders are randomly stored, but DTC P0300 is not stored, it indicates that misfires have been detected in different cylinders at different times. DTC P0300 is only stored 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 (immediately detection logic) and stores a DTC (2 trip detection logic) when either one of the following conditions, which could cause damage to the three-way catalytic converter, is detected.
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
| Required Sensors/Components (Main) | Crankshaft position sensor VVT sensor |
| Required Sensors/Components (Related) | Engine coolant temperature Intake air temperature sensor Mass air flow meter sub-assembly |
| Frequency of Operation | Continuous |
TYPICAL ENABLING CONDITIONS
| Intake air temperature | Higher than -10°C (14°F) |
| Either of the following conditions is met | A or B |
| A. Engine coolant temperature at engine start | Higher than -7°C (19°F) |
| B. Engine coolant temperature | Higher than 20°C (68°F) |
| Duration | Crankshaft 1000 revolutions x 4 |
| Duration | Crankshaft 200 revolutions x 3 |
CONFIRMATION DRIVING PATTERN
Connect the GTS to the DLC3.
Turn the engine switch on (IG).
Turn the GTS on.
Record the DTC(s) and freeze frame data.
Clear the DTCs (even if no DTCs are stored, perform the clear DTC procedure).
Using the GTS, switch the ECM from normal mode to check mode.
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.
Drive the vehicle so that the vehicle conditions displayed in Misfire RPM and Misfire Load of the Data List are the same as the freeze frame data. Perform this step several times.
Tech Tips
In order to store misfire DTCs, it is necessary to operate the vehicle for the period of time shown in the table below, confirm the Misfire RPM and Misfire Load in the Data List.
| Engine speed | Duration |
|---|---|
| Idling | 8.0 minutes or more |
| 1000 | 4.5 minutes or more |
| 2000 | 2.5 minutes or more |
| 3000 | 1.5 minutes or more |
Check whether misfires have occurred by checking DTCs and freeze frame data.
Tech Tips
Do not turn the engine switch off until the output 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 are cleared.
Record the DTC(s), freeze frame data and misfire counts.
Turn the engine switch off and wait for at least 30 seconds.
Clear the DTCs (even if no DTCs are stored, perform the clear DTC procedure).
CAUTION / NOTICE / HINT
Note
Inspect the fuses for circuits related to this system before performing the following procedure.
Tech Tips
If any DTCs other than misfire DTCs are output, troubleshoot those DTCs first.
Read freeze frame data using the GTS. 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:
There was insufficient fuel in the tank.
Improper fuel was used.
The spark plugs have been contaminated.
The problem requires further diagnosis.
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 stored again by performing 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:
Clear the DTCs.
Start the engine and conduct the confirmation driving pattern.
Read the misfiring counts of each cylinder or DTC(s) using the GTS.
Repair the cylinder(s) that has a high misfiring rate or is indicated by the DTC.
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 +/-15%, the air fuel ratio may be rich (-15% or less) or lean (+15% or higher).
When Coolant Temp in the freeze frame data is less than 75°C (167°F), the misfires have occurred only while warming up the engine.
An extremely imbalanced drive wheel which causes body vibration may cause misfire DTCs to be stored.
PROCEDURE
CHECK ANY OTHER DTCS OUTPUT (IN ADDITION TO MISFIRE DTCS)
Connect the GTS to the DLC3.
Turn the engine switch on (IG).
Turn the GTS on.
Enter the following menus: Powertrain / Engine / Trouble Codes.
Read the DTCs.
| Result | ||||||
|---|---|---|---|---|---|---|
|
Tech Tips
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 Click here |
| A |
|
CHECK PCV HOSE CONNECTIONS
Check the PCV hose connections.
| OK |
|---|
| PCV valve and hose are correctly connected and are not damaged. |
| Result | |||
|---|---|---|---|
|
| NG |
|
REPAIR OR REPLACE PCV HOSE |
| OK |
|
READ VALUE USING GTS (MISFIRE RPM AND MISFIRE LOAD)
Connect the GTS to the DLC3.
Turn the engine switch on (IG).
Turn the GTS on.
Enter the following menus: Powertrain / Engine / Data List / All Data / Misfire RPM and Misfire Load.
| Tester Display |
|---|
| Misfire RPM |
| Misfire Load |
Read and note the Misfire RPM and Misfire Load values.
Tech Tips
The Misfire RPM and Misfire Load values indicate the vehicle conditions under which the misfire occurred.
| Result | ||
|---|---|---|
|
| NEXT |
|
READ VALUE USING GTS (CATALYST OT MF F/C)
Connect the GTS to the DLC3.
Turn the engine switch on (IG).
Turn the GTS on.
Enter the following menus: Powertrain / Engine / Data List / All Data / Catalyst OT MF F/C.
| Tester Display |
|---|
| Catalyst OT MF F/C |
Read the value displayed on the GTS.
| Result | ||||||||
|---|---|---|---|---|---|---|---|---|
|
| B |
|
GO TO STEP 6 Click here |
| A |
|
PERFORM ACTIVE TEST USING GTS (PROHIBIT THE CATALYST OT MISFIRE PREVENT F/C)
Connect the GTS to the DLC3.
Turn the engine switch on (IG).
Turn the GTS on.
Enter the following menus: Powertrain / Engine / Active Test / Prohibit the Catalyst OT Misfire prevent F/C.
| Tester Display |
|---|
| Prohibit the Catalyst OT Misfire prevent F/C |
Perform the Active Test.
Note
When performing the Active Test, make sure the vehicle is stopped and the engine is either idling or being revved within 3000 rpm.
| Result | ||
|---|---|---|
|
| NEXT |
|
CHECK MISFIRE COUNT OF PORT INJECTION
Connect the GTS to the DLC3.
Start the engine and warm it up.
Turn the GTS on.
Enter the following menus: Powertrain / Engine / Active Test / Control the Injection Way / Port / Injection Way and Cylinder #1 Misfire Count to Cylinder #6 Misfire Count.
| Active Test Display |
|---|
| Control the Injection Way |
| Data List Display |
|---|
| Injection Way |
| Cylinder #1 Misfire Count |
| Cylinder #2 Misfire Count |
| Cylinder #3 Misfire Count |
| Cylinder #4 Misfire Count |
| Cylinder #5 Misfire Count |
| Cylinder #6 Misfire Count |
Allow the engine to idle.
Read each value for Cylinder #1 Misfire Count to Cylinder #6 Misfire Count and Injection Way displayed on the GTS. 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 GTS (Misfire RPM and Misfire Load)" procedures above [A].
Read the Injection Way and Cylinder #1 Misfire Count to Cylinder #6 Misfire Count or DTCs displayed on the GTS [B].
| Result | |||||||||
|---|---|---|---|---|---|---|---|---|---|
|
| B |
|
CHECK MISFIRE COUNT OF DIRECT INJECTION Click here |
| A |
|
CHECK MISFIRE COUNT OF DIRECT INJECTION
Connect the GTS to the DLC3.
Start the engine and warm it up.
Turn the GTS on.
Enter the following menus: Powertrain / Engine / Active Test / Control the Injection Way / Direct / Injection Way and Cylinder #1 Misfire Count to Cylinder #6 Misfire Count.
| Active Test Display |
|---|
| Control the Injection Way |
| Data List Display |
|---|
| Injection Way |
| Cylinder #1 Misfire Count |
| Cylinder #2 Misfire Count |
| Cylinder #3 Misfire Count |
| Cylinder #4 Misfire Count |
| Cylinder #5 Misfire Count |
| Cylinder #6 Misfire Count |
Allow the engine to idle.
Read each value for Cylinder #1 Misfire Count to Cylinder #6 Misfire Count and Injection Way displayed on the GTS. 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 GTS (Misfire RPM and Misfire Load)" procedures above [A].
Read the Injection Way and Cylinder #1 Misfire Count to Cylinder #6 Misfire Count or DTCs displayed on the GTS [B].
| Result | |||||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
|
|||||||||||||||||
| A |
|
GO TO STEP 12 Click here |
| B |
|
GO TO STEP 15 Click here |
| C |
|
REPLACE FUEL INJECTOR ASSEMBLY (FOR PORT INJECTION (MISFIRING CYLINDER)) Click here |
| D |
|
CHECK FUEL PRESSURE (FOR LOW PRESSURE SIDE)
Check the fuel pressure (for low pressure side).
| Result | |||
|---|---|---|---|
|
| OK |
|
REPLACE FUEL INJECTOR ASSEMBLY (FOR PORT INJECTION (MISFIRING CYLINDER)) Click here |
| NG |
|
CHECK FURL PUMP OPERATION (FOR LOW PRESSURE SIDE)
Check the fuel pump operation (for low pressure side).
| Result | |||
|---|---|---|---|
|
| OK |
|
CHECK AND REPLACE FUEL SYSTEM (PRESSURE REGULATOR, PIPE LINE AND FILTER) |
| NG |
|
REPLACE FUEL PUMP (FOR LOW PRESSURE SIDE) Click here |
CHECK MISFIRE COUNT OF DIRECT INJECTION
Connect the GTS to the DLC3.
Start the engine and warm it up.
Turn the GTS on.
Enter the following menus: Powertrain / Engine / Active Test / Control the Injection Way / Direct / Injection Way and Cylinder #1 Misfire Count to Cylinder #6 Misfire Count.
| Active Test Display |
|---|
| Control the Injection Way |
| Data List Display |
|---|
| Injection Way |
| Cylinder #1 Misfire Count |
| Cylinder #2 Misfire Count |
| Cylinder #3 Misfire Count |
| Cylinder #4 Misfire Count |
| Cylinder #5 Misfire Count |
| Cylinder #6 Misfire Count |
Allow the engine to idle.
Read each value for Cylinder #1 Misfire Count to Cylinder #6 Misfire Count and Injection Way displayed on the GTS. 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 GTS (Misfire RPM and Misfire Load)" procedures above [A].
Read the Injection Way and Cylinder #1 Misfire Count to Cylinder #6 Misfire Count or DTCs displayed on the GTS [B].
| Result | |||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|
|
|||||||||||
| A |
|
REPLACE FUEL INJECTOR ASSEMBLY (FOR DIRECT INJECTION (MISFIRING CYLINDER)) Click here |
| B |
|
CHECK MISFIRE COUNT
Connect the GTS to the DLC3.
Turn the engine switch on (IG) and turn the GTS on.
Clear the DTCs.
Start the engine and warm it up.
Enter the following menus: Powertrain / Engine / Data List / Misfire RPM, Misfire Load, Cylinder #1 to #6 Misfire Count and Injection Way.
| Tester Display |
|---|
| Injection Way |
| Cylinder #1 Misfire Count |
| Cylinder #2 Misfire Count |
| Cylinder #3 Misfire Count |
| Cylinder #4 Misfire Count |
| Cylinder #5 Misfire Count |
| Cylinder #6 Misfire Count |
| Misfire RPM |
| Misfire Load |
Drive the vehicle with Misfire RPM and Misfire Load.
Monitor all of the misfire count values or DTCs displayed on the GTS.
| Result | |||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
|
| A |
|
CHECK FOR INTERMITTENT PROBLEMS Click here |
| C |
|
CHECK INTAKE SYSTEM Click here |
| D |
|
REPLACE FUEL INJECTOR ASSEMBLY (FOR DIRECT INJECTION (MISFIRING CYLINDER)) Click here |
| B |
|
INSPECT SPARK PLUG
Inspect the spark plug of the misfiring cylinder.
| Result | |||
|---|---|---|---|
|
| NG |
|
REPLACE SPARK PLUG Click here |
| OK |
|
CHECK FOR SPARK (SPARK TEST)
Perform a spark test.
Tech Tips
If the result of the spark test is normal, proceed to the next step.
| Result | ||
|---|---|---|
|
| NEXT |
|
CHECK CYLINDER COMPRESSION PRESSURE
Measure the cylinder compression pressure of the misfiring cylinder.
| Result | |||
|---|---|---|---|
|
| OK |
|
REPLACE ECM Click here |
| NG |
|
CHECK ENGINE TO DETERMINE CAUSE OF LOW COMPRESSION |
CHECK INTAKE SYSTEM
Check the intake system for vacuum leaks.
| OK |
|---|
| No leaks from intake system. |
| Result | |||
|---|---|---|---|
|
| NG |
|
REPAIR OR REPLACE INTAKE SYSTEM |
| OK |
|
READ VALUE USING GTS (COOLANT TEMP)
| Result | |||
|---|---|---|---|
|
Connect the GTS to the DLC3.
Turn the engine switch on (IG).
Turn the GTS on.
Enter the following menus: Powertrain / Engine / Data List / All Data / Coolant Temp.
| Tester Display |
|---|
| Coolant Temp |
Read the Data List twice, when the engine is both cold and warmed up.
| Standard | ||||||||
|---|---|---|---|---|---|---|---|---|
|
| Result | |||
|---|---|---|---|
|
| NG |
|
REPLACE ENGINE COOLANT TEMPERATURE SENSOR Click here |
| OK |
|
READ VALUE USING GTS (MAF)
| Result | |||
|---|---|---|---|
|
Connect the GTS to the DLC3.
Start the engine.
Turn the GTS on.
Enter the following menus: Powertrain / Engine / Data List / All Data / MAF, Coolant Temp and Engine Speed.
| Tester Display |
|---|
| Engine Speed |
| MAF |
| Coolant Temp |
Allow the engine to idle until Coolant Temp reaches 75°C (167°F) or higher.
Read MAF with the engine speed at 3000 rpm.
| Standard | ||||||
|---|---|---|---|---|---|---|
|
| Result | |||
|---|---|---|---|
|
| NG |
|
CHECK HARNESS AND CONNECTOR (MASS AIR FLOW METER SUB-ASSEMBLY CONNECTOR CONNECTION) Click here |
| OK |
|
CHECK VALVE TIMING (CHECK FOR LOOSE TIMING CHAIN AND JUMPED TEETH)
| Result | |||
|---|---|---|---|
|
Remove the cylinder head cover sub-assemblies RH and LH.
| *a | Timing Mark | - | - |
Turn the crankshaft pulley, and align its groove with the "0" timing mark of the timing chain cover.
Check that the timing marks of the camshaft timing gear assemblies and camshaft timing exhaust gear assemblies are aligned with the timing marks of the bearing cap as shown in the illustration.
Tech Tips
If the timing marks are not as shown, turn the crankshaft one revolution clockwise.
| OK |
|---|
| The timing marks on the camshaft timing gear assemblies and camshaft timing exhaust gear assemblies are aligned as shown in the illustration. |
| Result | |||
|---|---|---|---|
|
| NG |
|
ADJUST VALVE TIMING Click here |
| OK |
|
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.
Tech Tips
Repair any problems.
| Result | ||
|---|---|---|
|
| NEXT |
|
CHECK WHETHER DTC OUTPUT RECURS (MISFIRE DTCS)
Connect the GTS to the DLC3.
Turn the engine switch on (IG).
Turn the GTS on.
Clear the DTCs.
Turn the engine switch off and wait for at least 30 seconds.
Start the engine and warm it up.
Turn the GTS on.
Drive the vehicle in accordance with the driving pattern described in Confirmation Driving Pattern.
Enter the following menus: Powertrain / Engine / Utility / All Readiness.
| Tester Display |
|---|
| All Readiness |
Input the DTC: P0300, P0301, P0302, P0303, P0304, P0305 or P0306.
Check the DTC judgment result.
| Result | ||||||
|---|---|---|---|---|---|---|
|
| B |
|
END |
| A |
|
CHECK HARNESS AND CONNECTOR (MASS AIR FLOW METER SUB-ASSEMBLY - ECM)
| Result | |||
|---|---|---|---|
|
Disconnect the mass air flow meter sub-assembly connector.
Disconnect the ECM connector.
Measure the resistance according to the value(s) in the table below.
| Standard Resistance | ||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
|
| Result | |||
|---|---|---|---|
|
| NG |
|
REPAIR OR REPLACE HARNESS OR CONNECTOR |
| OK |
|
REPLACE MASS AIR FLOW METER SUB-ASSEMBLY
Replace the mass air flow meter sub-assembly.
Tech Tips
If the results of the inspections performed in step 17 indicated no problem, proceed to the next step without replacing the mass air flow meter sub-assembly.
| Result | ||
|---|---|---|
|
| NEXT |
|
CONFIRM WHETHER MALFUNCTION HAS BEEN SUCCESSFULLY REPAIRED
Connect the GTS to the DLC3.
Turn the engine switch on (IG).
Turn the GTS on.
Clear the DTCs.
Turn the engine switch off and wait for at least 30 seconds.
Start the engine and warm it up.
Turn the GTS on.
Drive the vehicle in accordance with the driving pattern described in Confirmation Driving Pattern.
Enter the following menus: Powertrain / Engine / Utility / All Readiness.
| Tester Display |
|---|
| All Readiness |
Input the DTC: P0300, P0301, P0302, P0303, P0304, P0305 or P0306.
Check the DTC judgment result.
| Result | ||||||
|---|---|---|---|---|---|---|
|
| A |
|
END |
| B |
|
REPLACE ECM Click here |