DTC Description

The PCM must monitor the engine for misfiring possibly caused by ignition coil defects or injector fails. If misfiring is detected, the PCM identify the cylinder (s) that has (have) misfired and calculate misfiring rate for a given duration. The DTC for Misfire (P0301 to 0304) is set as soon as misfiring rate exceed the limit which result in damage to the catalyst or increase emissions. The PCM stores individual DTC for the cylinder has more than 10% of total misfire rate. With more than two cylinders misfire detection, the PCM sets P0300.

If the misfire rate is not extremely high, the MIL will be illuminated in the next driving cycle that diagnostic runs and fails. With extremely high misfire rate which has a danger of burning up the catalyst, the MIL blinks immediately.