GMC Yukon 2021 Owner's Manual page 37

36 Keys, Doors, and Windows
Press or pull (2) again to stop at the
desired location.
Sunroof Vent Operation:
Press and release (3) to vent the
sunroof.
Pull and release (3) to close the
sunroof vent.
Automatic Reversal System
The sunroof and power sunshade,
if equipped, have an automatic reversal
system that is only active when the sunroof
and power sunshade are operated in
express-close mode.
If an object is in the path while
express-closing, the reversal system will
detect an object, stop, and open the sunroof
or power sunshade slightly.
If this condition occurs, attempt to remove
the object, then pull and release the switch
to express close. If the reversal occurs
multiple times, the DIC message OPEN THEN
CLOSE SUNROOF will display, and express is
disabled. To operate sunroof while express is
disabled, the switch must be either pressed
or pulled and held.
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.