It is better not to park with the vehicle running. If the vehicle is left while running, follow the proper steps to be sure the vehicle will not move and there is adequate ventilation.
See Shifting Into Park and Engine Exhaust.
If the vehicle is left parked while running and the Remote Keyless Entry (RKE) transmitter is outside the vehicle, the vehicle will turn off after one hour. If the vehicle is left parked while running and the RKE transmitter is inside, the vehicle will turn off after two hours.
The timer will reset if the vehicle is taken out of P (Park) while it is running.
Shifting out of Park
Engine Exhaust#99-09-40-005G: Seat Belt Extender Availability - (Aug 15, 2013) Primary Seat Belts
Subject:Seat Belt Extender AvailabilityModels: 2014 and Prior GM Cars and Trucks This bulletin has been revised to add the 2012-2014 model years. Please discard CorporateBulletin Number 99-09-40-005F.Important:DO NOT use belt extenders when securing a child restraint.The seat and shoulder belt r ...