GMC Yukon 2012 Owner's Manual page 62

2-24 Keys, Doors, and Windows
Vent: From the closed position,
press the rear of switch (B) to vent
the sunroof.
Open/Close: To open the sunroof,
press and hold switch (A) until the
sunroof reaches the desired
position. Press and hold the front
of switch (A) to close it.
Express-Open/Express-Close:
To express-open the sunroof,
fully press and release the rear
of switch (A) until the sunroof
reaches the desired position.
To express-close the sunroof, fully
press and release the front of
switch (A). Press the switch again
to stop it.
When the sunroof is opened, an
air deflector will automatically raise.
The air deflector will retract when
the sunroof is closed.
The sunroof also has a sunshade
which can be pulled forward to block
sun rays. The sunshade must be
opened and closed manually.
If an object is in the path of the
sunroof while it is closing, the
anti-pinch feature will detect the
object and stop the sunroof.
Dirt and debris may collect on the
sunroof seal or in the track. This
could cause an issue with sunroof
operation or noise. It could also
plug the water drainage system.
Periodically open the sunroof and
remove any obstacles or loose
debris. Wipe the sunroof seal and
roof sealing area using a clean
cloth, mild soap, and water. Do not
remove grease from the sunroof.