Monitoring the misfire

Discovered accidentally misfiring (P0300), detected misfiring cylinder (P0301, P0302, P0303, P0304)

The PCM controls the time interval of the input signal of the crankshaft position sensor. The PCM calculates the change of the time interval for each cylinder. If you change the time interval exceeds the pre-programmed value, the PCM detects a misfire in the corresponding cylinder. During engine operation the PCM counts the number of misfires that have occurred in every 200 and 1,000 crankshaft revolutions and calculates the misfire for each revolution of the crankshaft. If the ratio exceeds the preprogrammed value, the PCM determines that a misfire has occurred, which may result in damage to the catalyst or to influence the emission characteristics.