Clarified Issue Statement
G1000 systems installed in Cessna Mustang aircraft with GDU Software Versions 15.00 and later are affected.
EDM will only work if the autopilot vertical mode is set to FLC before an EDM activation. EDM will not descend the aircraft as intended if the autopilot is coupled to any other vertical mode.
In the event of cabin depressurization follow the published AFM emergency descent procedure.
This issue will be fixed in a later software version.