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DTC P0300-P0304 (LDK with Turbocharger)

DTC P0300-P0304 (LDK with Turbocharger)

Diagnostic Instructions


Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure.

Review Strategy Based Diagnosis for an overview of the diagnostic approach.

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 in order to determine when an engine misfire is occurring and uses information from the camshaft position sensor in order to determine which cylinder is misfiring. By monitoring variations in the crankshaft rotation speed for each cylinder, the ECM is able to detect individual misfire events. If the ECM detects a misfire rate sufficient to cause emission levels to exceed mandated standards, DTC P0300 sets. Under certain driving conditions, a misfire rate can be high enough to cause the 3-way catalytic converter to overheat, possibly damaging the converter. The Malfunction Indicator Lamp (MIL) flashes when conditions arise to cause overheating damage to the converter and DTC P0300 is set. DTC P0301 to P0304 correspond to the cylinders 1-4. If EC; can determine that a specific cylinder is misfiring, the DTC for that cylinder will be set.

Conditions for Running the DTC


DTCs P0121, P0122, P0123, P0221, P0222, P0335, or P0336 are not set.

The engine speed is between 400-7,000 RPM.

The engine coolant temperature (ECT) is greater than -30°C (-22°F).

The fuel level is more than 11 %.

The ECM is not in fuel shut-off or decel fuel cut-off mode.

DTCs P0300, and P0301-P0304 run continuously when the above conditions are met.


Conditions for Setting the DTC

The ECM is detecting a crankshaft rotation speed variation indicating a misfire sufficient to cause emission or catalytic converter damaging levels to exceed mandated standards.

Action Taken When the DTC Sets


DTCs P0300-P0304 are Type B DTCs.

When the MIL is flashing, the injector may be disabled for the misfiring cylinder to protect the catalytic converter. Depending on the conditions that set the code, the engine may go into Open Loop.


Conditions for Clearing the MIL/DTC


DTCs P0300-P0304 are Type B DTCs.

The DTC must pass under the same conditions that were present when the DTC failed.


Diagnostic Aids


A misfire may only occur when the engine is 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

- A damaged accessory drive component or belt

- A damaged reluctor wheel


Reference Information

Schematic Reference

Engine Controls Schematics

Connector End View Reference

Component Connector End Views

Electrical Information Reference


Circuit Testing

Connector Repairs

Testing for Intermittent Conditions and Poor Connections

Wiring Repairs


DTC Type Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Scan Tool Reference

Control Module References for scan tool information

Special Tools


J 26792 HEI Spark Tester

For equivalent regional tools, refer to Special Tools .


Circuit/System Verification


1. Verify that no other DTCs are set.

2. If a DTC is set, refer to Diagnostic Trouble Code (DTC) List - Vehicle .

3. Engine idling, verify there is no abnormal engine noise.

4. If there is abnormal engine noise, refer to Symptoms - Engine Mechanical .

5. Observe the Current Misfire Counters with a scan tool. The Current Misfire Counters should not be incrementing. Random misfires that are not steadily incrementing may be normal.

6. If the vehicle passes the circuit/system verification test, use the vehicle during the conditions when the DTC occurred. You may also use the vehicle under the conditions gathered in the Freeze Frame/Failure Records list.


Circuit/System Testing


1. Verify that the following conditions do not exist:

Engine vacuum leaks

Fuel pressure that is too low or too high-Refer to Fuel System Diagnosis .

Contaminated fuel-Refer to Alcohol/Contaminants-in-Fuel Diagnosis .

Restricted exhaust system-Refer to Restricted Exhaust .

If you find any of the above conditions, repair as necessary.

2. Ignition OFF, remove the T8 ignition coil from the misfiring cylinder, leaving the electrical connector connected.

3. Install the J 26792 Spark Tester to the boot of the T8 ignition coil and ground.

4.
Note

An erratic or weak spark is considered a no spark condition.


Attempt to start the engine and observe the J 26792 Spark Tester. The spark tester should spark.

5. If there is no spark, refer to Electronic Ignition System Diagnosis (LDK with Turbocharger) for diagnosis of the T8 ignition coil.

6. Ignition OFF, remove the spark plug from the misfiring cylinder. Verify that the following conditions do not exist with the spark plug:

Gas, coolant, or oil fouled

Cracked, worn, incorrectly gapped

7. If there is a condition with the spark plug, replace the spark plug.

8. Exchange the suspected spark plug with another cylinder that is operating correctly.

9. Operate the engine under the conditions in which the misfire occurred. Observe the Current Misfire Counters with a scan tool. The misfire should not follow the spark plug exchange.

10. If the misfire follows the spark plug, replace the spark plug.

11. If all conditions test normal, test or inspect for the following:

A lean or rich fuel injector-Refer to Fuel Injector Solenoid Coil Test .

An engine mechanical condition-Refer to Symptoms - Engine Mechanical .


Repair Instructions


Ignition Coil Replacement

Spark Plug Replacement


Repair Verification


1. Install any components or connectors that have been removed or replaced during diagnosis.

2. Perform any adjustment, programming or setup procedures that are required when a component or module is removed or replaced.

3. Clear the DTCs.

4. Turn OFF the ignition for 60 s.

5. If the repair was related to a DTC, duplicate the Conditions for Running the DTC and use the Freeze Frame/Failure Records, if applicable, in order to verify the DTC does not reset. If the DTC resets or another DTC is present, refer to the Diagnostic Trouble Code (DTC) List - Vehicle and perform the appropriate diagnostic procedure.

6. 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 DTC P0420 .