GMC Terrain: Keys and Locks / Delayed Locking
This feature delays the actual locking of the doors until five seconds after all doors are closed.
Delayed locking can only be turned on when the Open Door Anti-Lockout feature has been turned off.
When 
is pressed on the power
door lock switch with the door open,
a chime will sound three times
indicating that delayed locking is
active.
The doors will then lock automatically five seconds after all doors are closed. If a door is reopened before five seconds have elapsed, the five-second timer will reset once all the doors are closed again.
Press 
on the door lock switch
again, or press 
on the RKE
transmitter, to override this feature
and lock the doors immediately.
Delayed locking can be programmed. See Vehicle Personalization.
Automatic Door Locks
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)...
Other information:
GMC Terrain 2018-2025 Owners Manual: Speedometer, Odometer, Trip Odometer and Tachometer
Speedometer The speedometer shows the vehicle's speed in either kilometers per hour (km/h) or miles per hour (mph). Odometer The odometer shows how far the vehicle has been driven, in either kilometers or miles. Trip Odometer The trip odometer shows how far the vehicle has been driven since the trip odometer was last reset...
GMC Terrain 2018-2025 Owners Manual: Windows
Warning Never leave a child, a helpless adult, or a pet alone in a vehicle, especially with the windows closed in warm or hot weather. They can be overcome by the extreme heat and suffer permanent injuries or even death from heat stroke. The vehicle aerodynamics are designed to improve fuel economy performance...