DTC P0300-P0304 or P0313. Saturn Astra 2008

For 1990-2009 cars only

Makes 🢒 Saturn 🢒 2008 🢒 Astra 🢒 Safety and Security 🢒 Supplemental Inflatable Restraints 🢒 DTC P0300-P0304 or P0313

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 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

DTC P0313: Misfire Detected With Low Fuel Level

Circuit/System Description

The engine control module (ECM) uses information from the crankshaft position (CKP) sensor in order to determine when an engine misfire is occurring and uses information from the camshaft position (CMP) 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 (TWC) to overheat, possibly damaging the converter. The malfunction indicator lamp (MIL) will flash ON and OFF when converter overheating, damaging conditions are present and DTC P0300 is set. DTCs P0301-P0304 correspond to cylinders 1-4. If the ECM is able to determine that a specific cylinder is misfiring, the DTC for that cylinder will set. If the ECM detects a misfire and low fuel level, DTC P0313 is set.

Conditions for Running the DTC

•	DTCs P0016, P0101, P0102, P0103, P0121, P0122, P0123, P0221, P0222, P0223, P0335, P0336 or P1101 are not set.

•	The engine speed is between 600-6,528 RPM.

•	The ECM is not in fuel cut-off mode.

•	DTCs P0300, P0304, and P0313 run continuously when the above conditions are met.

•	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

-	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

•	J 36012-A Ignition System Diagnosis Harness

Circuit/System Verification

Verify that no other DTCs are set.

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

Engine idling, verify there is no abnormal engine noise.

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

If the vehicle passes the Circuit/System Verification test, operate the vehicle within the Conditions for Running the DTC. You may also operate the vehicle within the conditions that are captured in the Freeze Frame/Failure Records lists.

Circuit/System Testing

Verify that the following conditions do not exist:

•	Low fuel level

•	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.

Ignition OFF, disconnect the harness connector from the DIS-ignition module.
Remove the DIS-ignition module from the engine.
After removing the DIS-ignition module from the engine, connect the engine wire harness to the DIS-ignition module.
Install the J 36012-A onto each spark plug and secure the ends into the DIS-ignition module spark plug boots for testing.
Install a J 26792 into the position #1 of the DIS-ignition module and ground.

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

Crank the engine and observe the J 26792 . The spark tester should spark.
Ignition OFF, remove the Spark Tester and repeat the test for each cylinder.

⇒	If there is no spark, refer to Electronic Ignition (EI) System Diagnosis for diagnosis of the DIS-ignition module.

Ignition OFF, inspect each spark plug. If there is a condition with the spark plug, replace the spark plug. Refer to Ignition System Specifications and Spark Plug Inspection.

Repair Instructions

•	Ignition Coil Replacement

•	Spark Plug Replacement

Repair Verification

Install any components or connectors that have been removed or replaced during diagnosis.
Perform any adjustment, programming or setup procedures that are required when a component or module is removed or replaced.
Clear the DTCs.
Turn OFF the ignition for 60 seconds.
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.
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.