P0301A Cylinder #1,#2,#3,#4,#5 Or #6 Misfire

NAME OF CODE
Cylinder #1, #2, #3, #4, #5, #6 Misfire

WHEN MONITORED
With the engine running, after successfully performing a crank sensor learn.

SET CONDITION
When more than a 2% misfire rate is measured during two trips, or with a 10% to 30% misfire rate during one trip.

THEORY OF OPERATION
Misfire is detected by the crankshaft speed fluctuation (CSF) method. This method compares the engine speed difference between the cylinders in firing order. The speed is detected by the crankshaft position sensor. An RPM value is set for each cylinder for comparison. When an RPM difference of more than 10 RPM between cylinders, a misfire count of 1 is recorded. The RPM can vary 1 to 10 RPM depending on engine load. Two types of misfire are detected: a two-trip misfire, which is about 2% and results in an emissions increase, or a one-trip misfire, which is about 10-30% and will cause damage to the catalytic converter.

POSSIBLE CAUSES
- Secondary ignition wires
- Faulty connections
- Spark plug, wire, or connector
- Mechanical engine problem
- Injectors
- PCM
- Ignition coil circuit
- Contaminated fuel