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#PIT4720C: Odometer Servicing When The Odometer Cannot Be Set To The Actual Mileage - (May 2, 2013) Gauges Odometer
Subject:Odometer Servicing When The Odometer Cannot Be Set To The Actual MileageModels: 2014 and Prior GM Passenger Cars and Trucks This PI was superseded to update model years. Please discard PIT4720B.The following diagnosis might be helpful if the vehicle exhibits the symptom(s) describedin th ...