Cadillac 2011 DTS Owner's Manual page 161

To close the sunroof, operate the controls
according to one of the following:
From the open position, press and hold the driver
side sunroof switch forward. The sunshade must
be closed manually.
From the vent position, press and hold the
passenger side sunroof switch rearward.
Dirt and debris may collect on the sunroof seal or in the
tracks that could cause an issue with sunroof operation,
noise or 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 sunroof.
3-57