Buick 2009 Enclave - Manual (Page 239)

Multi-Band Antenna
The multi-band antenna is located
on the roof of the vehicle. This type
of antenna is used with the AM/FM
radio, as well as OnStar
® and the
XM™ Satellite Radio Service
System, if the vehicle has these
features. Keep this antenna clear
of snow and ice build up for clear
radio reception. If the vehicle has
a sunroof, the performance of the
radio system may be affected if the
sunroof is open. Loading items onto
the roof of the vehicle can interfere
with the performance of the radio
system and, if the vehicle has this
feature, OnStar
® . Make sure the
multi-band antenna is not obstructed.
Instrument Panel 3-121