See also:

Ignition Transmission Lock Check
While parked, and with the parking brake set, try to turn the ignition to LOCK/OFF in each shift lever position. The ignition should turn to LOCK/OFF only when the shift lever is in P (Park). ...

OnStar Mobile App
With an iPhone® or Android™-based mobile device, an OnStar mobile app can be downloaded. The vehicle can be remote started, if equipped, or the doors can be unlocked from anywhere there ...

Door Locks
To lock or unlock the door, use the Remote Keyless Entry (RKE) transmitter or the key from outside the vehicle, and the door lock knob or switch from inside the vehicle. To unlock or lock the fuel do ...