P0306

DTC P0300-P0308

DIAGNOSTIC INSTRUCTIONS
- Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure. Initial Inspection and Diagnostic Overview
- 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

DTC P0305
Cylinder 5 Misfire Detected

DTC P0306
Cylinder 6 Misfire Detected

DTC P0307
Cylinder 7 Misfire Detected

DTC P0308
Cylinder 8 Misfire Detected

CIRCUIT/SYSTEM DESCRIPTION
The engine control module (ECM) monitors changes in crankshaft speed using input from the crankshaft position sensor. The ECM adjusts the fuel delivery to each cylinder in order to minimize crankshaft speed changes. If the ECM identifies a cylinder or cylinders requiring an excessive amount of fuel in order to maintain the correct crankshaft speed, a DTC will set.

CONDITIONS FOR RUNNING THE DTC

P0300
- The engine is running at idle for more than 10 seconds.
- The engine coolant temperature (ECT) is more than 40°C (104°F).
- DTC P0300 runs once per ignition cycle when the above conditions are met.
- DTCs P0301-P0308 must run before DTC P0300 runs.

P0301-P0308
- DTCs P0117, P0118, P0335, P0336, P0502, P2146, P2149, P2152, P2155 and P062C are not set.
- The ECT is more than 40°C (104°F).
- The engine is running at idle for more than 10 seconds.
- The engine RPM is between 500-1,500 RPM.
- The vehicle speed is less than 3 mph.
- The calculated fuel rate is between 3 cu.mm and 25 cu.mm.
- DTCs P0301-P0308 will run once per ignition cycle in a total of 440 engine revolutions when the above conditions are met.

CONDITIONS FOR SETTING THE DTC
Cylinder RPM is less than the minimum average cylinder speed after an injection event counted 180 times.

ACTIONS TAKEN WHEN THE DTC SETS
DTC P0300, P0301, P0302, P0303, P0304, P0305, P0306, P0307, and P0308 are type B DTCs.

CONDITIONS FOR CLEARING THE MIL/DTC
DTC P0300, P0301, P0302, P0303, P0304, P0305, P0306, P0307, and P0308 are type B DTCs.

CIRCUIT/SYSTEM TESTING
1. Unplug the fuel injector for the cylinder that indicated the misfire.
2. Start the engine. Record the DTCs that set. The appropriate injector control circuit DTC P0201-P0208 should set.
- If the appropriate injector control circuit DTC did not set replace the ECM.
3. Reconnect the injector and clear the DTCs. 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 List.
- If any DTCs other than P0300-P0308 are set, diagnose those DTCs first.
- If only DTC P0300-P0308 are set, go to Fuel Injector Balance Test with Tech 2 (Automatic Transmission) Fuel Injector Balance Test with Tech 2 (Manual Transmission). Fuel Injector Balance Test with Tech 2 (Automatic Transmission) Fuel Injector Balance Test with Tech 2 (Manual Transmission)

REPAIR INSTRUCTIONS
Perform the Diagnostic Repair Verification Diagnostic Repair Verification after completing the repair. Verification Tests

Control Module References for replacement, setup, and programming. Programming and Relearning