GMC Terrain: Sunroof - Roof - Keys, Doors, and Windows - GMC Terrain Owner's ManualGMC Terrain: Sunroof

On vehicles with a sunroof, the switches used to operate it are on the headliner above the rearview mirror. The ignition must be in ON/ RUN or ACC/ACCESSORY, or in Retained Accessory Power (RAP) to operate the sunroof. See Ignition Positions on page 9‑21 and Retained Accessory Power (RAP) on page 9‑25.

○ Press and hold the front or rear of the driver side switch to open or close

○ Press and hold the front or rear of the driver side switch to open or close the sunroof. The sunshade automatically opens with the sunroof, but must be closed manually.

○ Press and hold the rear of the passenger side switch to vent the sunroof. Press and hold the front of the switch to close.

Roof
...

Express-open/Express-close
Press and release the front or rear of the driver side switch to express-open or express-close the sunroof. ...

See also:

SRS airbag deployment conditions
Front airbags ●The SRS front airbags will deploy in the event of an impact that exceeds the set threshold level (the level of force corresponding to an approximately 12 - 18 mph [20 - 30 km/h ...

Stowage compartments in the rear
Stowage compartment in the rear Do not sit or lean your bodyweight on the armrests when they are folded out as you could damage them. Close the cover of the stowage compartment before foldin ...

Seat belt pre-tensioner system and force limiter system
The driver’s seat and front passenger’s seat each have a seat belt equipped with a pre-tensioner system. Pre-tensioner system The pre-tensioner system will retract their respective seat belts ...