Engine Misfire Due to Failed Ignition Coil This Service Information bulletin supersedes SI M12 01 15 dated March 2016.. The Check Engine or Service Engine Soon (MIL) lamp is on with misfire fault(s) stored in the DME. Intermittent performance or rough running without a relevant DME fault stored The most likely cause is that an ignition coil has failed, which in many cases can be confirmed with basic diagnosis. During operation with high temperature fluctuations, the different materials used in the Bosch ignition coil construction can deteriorate over time, leading to a failure.
