This Preliminary information communicates Some customers may comment that the SES lamp is illuminated or was Illuminated and turned off. During inspection Technician may notice DTC P0300 (Engine Misfire Detected) active or stored in history. Customers may also comment that the check engine light was flashing while driving up a long grade or smooth road with steady throttle.  This condition may be caused by the P0300 diagnostic falsely setting the DTC under certain driving conditions. Upon reviewing GDS data you may notice misfires being recorded on any cylinder but may be more noticeable on cylinders 1 and 6.  Engineering is working on an updated calibration to address this concern.