The doors will lock automatically when all doors are closed, the ignition is on, and the vehicle is shifted out of P (Park).
If a vehicle door is unlocked and then opened and closed, the doors will lock either when your foot is removed from the brake or the vehicle speed becomes faster than 13 km/h (8 mph).
To unlock the doors:
Automatic door locking cannot be disabled. Automatic door unlocking can be programmed. See Vehicle Personalization.
#09-00-89-016C: Warranty Administration - Labor Operation 0600014 - Suspected Tampering or Vehicle Modifications - (May 6, 2013)
Subject:Warranty Administration – Labor Operation 0600014 – Suspected Tampering or VehicleModificationsModels: 2014 and Prior GM Passenger Cars and Trucks This bulletin is being revised to add the 2014 model year and update the labor operation.Please discard Corporate Bulletin Number 09-00-8 ...