What is P0305?
Diagnostic trouble code (DTC) P0305 is defined as “Cylinder 5 Misfire Detected.”
This diagnostic trouble code means your engine’s powertrain control module (PCM) has detected several misfire events on cylinder 5.
How does that happen?
The cylinders in your vehicle’s engine are responsible for generating power. The fuel injector injects fuel into these cylinders, which gets combusted by a spark from spark plugs. The resulting force from the fuel combustion is what drives the crankshaft and your wheels.
When these cylinders work together, the crankshaft’s RPM stays consistent. However, repeated misfires on any cylinder lead to a loss of engine power, rough idling, or hesitation during acceleration.
Your vehicle’s PCM constantly monitors the crankshaft’s RPM via the crankshaft position sensor signals. When it detects fluctuations in these signals due to a cylinder 5 misfire, it registers the DTC P0305 code and activates the check engine light (CEL).