OBD II regulations require that the OBD II system monitor the engine for misfire conditions and identify specific cylinders that experience a misfire. The PCM should also identify and set a different code to indicate if a multiple misfire condition exists. It should also be able to identify a specific cylinder that misfires in a multiple misfire condition. This monitor detects misfires related to engine mechanical, ignition or fuel system faults under positive load conditions (idle, cruise, etc.).