GMC TERRAIN 2018 Owner's Manual page 19

18 Radio
under heavy foliage, bridges,
garages, or tunnels may cause loss
of the SiriusXM signal for a period
of time.
Mobile Device Usage
Mobile device usage, such as
making or receiving calls, charging,
or just having the mobile device on
may cause static interference in the
radio. Unplug the mobile device or
turn it off if this happens.
Fixed Mast Antenna
The fixed mast antenna will go
through most car washes as long as
it is securely attached. If the
antenna becomes slightly bent,
straighten it out by hand. If it is
badly bent, replace it.
Occasionally check that the antenna
is tight at the base. If tightening is
required, protect the paint from
damage.
Multi-Band Antenna
The roof antenna is for OnStar and
GPS (Global Positioning System).
Keep clear of obstructions for clear
reception. If the vehicle has a
sunroof, and it is open, reception
can also be affected.