P0302
DTC P0300-P0304 (LDK, LHU With Turbocharger) (2.0L With Turbocharger)
Diagnostic Instructions
* Perform the Diagnostic System Check - Vehicle (Diagnostic System Check - Vehicle) prior to using this diagnostic procedure.
* Review Strategy Based Diagnosis (Strategy Based Diagnosis) for an overview of the diagnostic approach.
* Diagnostic Procedure Instructions (Diagnostic Procedure Instructions) provides an overview of each diagnostic category.
DTC Descriptors
DTC P0300
- Engine 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
Circuit/System Description
The engine control module (ECM) uses information from the crankshaft position sensor and the camshaft position sensors in order to determine when an engine misfire is occurring. By monitoring variations in the crankshaft rotation speed for each cylinder, the ECM is able to detect individual misfire events. A misfire rate that is high enough can cause 3-way catalytic converter damage. The malfunction indicator lamp (MIL) will flash ON and OFF when the conditions for catalytic converter damage are present. DTCs P0301 through P0304 correspond to cylinders 1 through 4. If the ECM is able to determine that a specific cylinder is misfiring, the DTC for that cylinder will set, and the corresponding fuel injector is disabled. The ECM will re-enable the fuel injector after 3 crankshaft revolutions when the misfire is not current. The ECM will re-enable the fuel injector after 6 crankshaft revolutions when the misfire is not current, if the vehicle is equipped with a manual transmission.
Conditions for Running the DTC
* DTC P0010, P0011, P0013, P0014, P0016, P0017, P0018, P0019, P0020, P0021, P0023, P0024, P0068, P0101, P0102, P0103, P0106, P0107, P0108, P0112, P0113, P0117, P0118, P0120, P0121, P0122, P0123, P0220, P0222, P0223, P0335, P0336, P0606, P0641, P0651, P1516, P2101, P2122, P2123, P2127, P2128 or P2176 is not set.
* When DTC P0315 is set, the engine speed must be more than 1,000 RPM.
* Engine run time is more than 2 crankshaft revolutions.
* The engine speed is between 450-6,600 RPM.
* The engine coolant temperature (ECT) is between -7 and +130°C (+19 and +266°F).
* When the startup ECT is colder than -7°C (+19°F), this diagnostic will be delayed until the ECT is warmer than +21°C (+69°F).
* The fuel level is more than 10 percent.
* The ECM is not in fuel shut-off, or decel fuel cut-off mode.
* The electronic brake control module (EBCM) and the traction control system (TCS) are not active or detecting rough road.
* An automatic transmission shift with a throttle position more than 95 percent is not occuring.
* The power management is not active.
* Excessive drive wheel slip is not detected.
* DTCs P0300 through P0304 run continuously when the above conditions exist for greater than 1,000 engine revolutions. 200 revolutions after the first failure.
Conditions for Setting the DTC
P0300
The ECM is detecting a crankshaft speed change indicating a random misfire is occuring that exceeds mandated emission level standards or is at catalytic converter damaging levels.
P0301, P0302, P0303, P0304
The ECM is detecting a crankshaft speed change indicating a single cylinder misfire is occuring that exceeds mandated emission level standards or is at catalytic converter damaging levels.
Action Taken When the DTC Sets
* DTCs P0300-P0304 are Type B DTCs.
* When the MIL is flashing the fuel injector may be disabled for the misfiring cylinder to protect the catalytic converter.
Conditions for Clearing the DTC
* DTCs P0300-P0304 are Type B DTCs.
* The DTC must run and pass under the same operating conditions that were present when the DTC failed.
Diagnostic Aids
* A misfire may only occur when the engine is operating under a load or when the engine is cold.
* A misfire DTC could be caused by an excessive vibration from sources other than the engine. Inspect for the following possible sources:
- A tire or wheel that is out of round or out of balance
- Variable thickness brake rotors
- An unbalanced drive shaft
- Certain rough road conditions
- Transmission operation
- A damaged reluctor wheel
- A damaged accessory drive component or belt ; remove the belt and safely operate the engine to evaluate
* High resistance in the circuits of the injectors may set a misfire DTC without setting an injector DTC. Test the injector circuits of the affected cylinder(s) for a high resistance if you suspect a condition.
* If the condition is intermittent, observing the scan tool IC Circuit Test and Fuel Injector Circuit Test Status parameters may help isolate the condition. The circuit test status parameters will change from OK or Not Run to Malfunction if a condition exists.
* A condition in the heated O2 sensor (HO2S) heater control circuits may set a DTC P0300.
Reference Information
Schematic Reference
Engine Controls Schematics ([1][2]Electrical Diagrams)
Connector End View Reference
Component Connector End Views (Connector End Views By Name)
Electrical Information Reference
* Circuit Testing (Circuit Testing)
* Connector Repairs (Connector Repairs)
* Testing for Intermittent Conditions and Poor Connections (Testing for Intermittent Conditions and Poor Connections)
* Wiring Repairs (Wiring Repairs)
DTC Type Reference
Powertrain Diagnostic Trouble Code (DTC) Type Definitions (Powertrain Diagnostic Trouble Code (DTC) Type Definitions)
Scan Tool Reference
Control Module References (Programming and Relearning) for scan tool information
Special Tools
* J 26792 - Spark Tester
* For equivalent regional tools, refer to Special Tools (Tools and Equipment).
Circuit/System Verification
1. Engine idling at the normal operating temperature.
• If there is an abnormal engine noise, refer to Symptoms - Engine Mechanical (Symptoms - Engine Mechanical).
2. Verify that no other DTCs are set.
• If a DTC is set, refer to Diagnostic Trouble Code (DTC) List - Vehicle (Diagnostic Trouble Code (DTC) List - Vehicle).
3. Observe the scan tool Current Misfire Cyl. 1-4 parameters. The Misfire Current Counters should not be incrementing.
4. Engine idling, perform the Cylinder Power Balance test with a scan tool to isolate the misfiring cylinder. The engine speed should change when each injector is disabled.
5. Operate the vehicle within the Conditions for Running the DTC to verify the DTC does not reset. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records data.
Circuit/System Testing
1. Verify that the following conditions do not exist:
* Vacuum hose splits, kinks, and incorrect connections
* Engine vacuum leaks
* Crankcase ventilation system for vacuum leaks
* Fuel pressure that is too low or too high-Refer to Fuel System Diagnosis (Fuel System Diagnosis).
* Contaminated fuel-Refer to Alcohol/Contaminants-in-Fuel Diagnosis (Alcohol/Contaminants-in-Fuel Diagnosis).
* Exhaust system restrictions-Refer to Restricted Exhaust (Restricted Exhaust).
• If you find any of the above conditions, repair as necessary.
2. Ignition OFF, remove the T8 ignition coil of the misfiring cylinder, leaving the electrical connector connected.
3. Inspect the ignition coil boot, verify that the following conditions do not exist:
* Holes
* Tears
* Carbon tracking
* Oil contamination
* Water intrusion
• If you find any of the above conditions, repair as necessary.
4. Install the J 26792 - Spark Tester to the boot of the appropriate T8 ignition coil and ground.
Note: An erratic or weak spark is considered a no spark condition.
5. Attempt to start the engine and observe the J 26792 - Spark Tester. The spark tester should spark.
• If there is no spark, refer to Electronic Ignition System Diagnosis (Electronic Ignition System Diagnosis) for diagnosis of the T8 ignition coil.
6. Ignition OFF, remove the spark plug from the misfiring cylinder. Inspect the spark plug, verify that the following conditions do not exist:
* Gas, coolant, or oil fouled-Refer to Spark Plug Inspection (Testing and Inspection).
* Cracked, worn, incorrectly gapped-Refer to Ignition System Specifications (Application and ID).
• If you find any of the above conditions, replace the spark plug.
7. Exchange the suspected spark plug with another cylinder that is operating correctly.
8. Engine idling, observe the scan tool Current Misfire Counter parameters. The misfire should not follow the spark plug exchange.
• If the misfire follows the spark plug, replace the spark plug.
9. Verify that the following conditions do not exist:
* A lean or rich Q17 fuel injector-Refer to Fuel Injector Balance Test (Fuel Injector Balance Test).
* An engine mechanical condition-Refer to Symptoms - Engine Mechanical (Symptoms - Engine Mechanical).
• If you find any of the above conditions, repair as necessary.
Repair Instructions
* Ignition Coil Replacement (Service and Repair)
* Spark Plug Inspection (Testing and Inspection)
* Spark Plug Replacement (Service and Repair)
Repair Verification
1. Perform the Diagnostic Repair Verification (Verification Tests) after completing the diagnostic procedure.
2. To verify that the performance of the catalytic converter has not been affected by the condition that set this DTC, perform the Repair Verification for DTC P0420. Refer to Diagnostic Trouble Code (DTC) List - Vehicle (Diagnostic Trouble Code (DTC) List - Vehicle) for DTC P0420.