GMC 2007 Sierra - Manual (Page 183)

Passenger Airbag Indicator
The mirror may be equipped with a passenger
airbag indicator on the mirror glass, just above the
buttons. If the vehicle has this feature the mirror
will display the word ON, or an airbag symbol
in Canada, when the passenger airbag is enabled.
For more information see Passenger Sensing
System on page 103
Cleaning the Mirror
When cleaning the mirror, use a paper towel or
similar material dampened with glass cleaner.
Do not spray glass cleaner directly on the mirror
as that may cause the liquid cleaner to enter
the mirror housing.
Outside Manual Mirrors
Adjust your outside mirrors so you can just see
the side of your vehicle and have a clear view of
objects behind you. The mirrors can be folded
in to enter narrow areas.
The use of hood-mounted air deflectors and
add-on convex mirror attachments may adversely
affect mirror performance.
Outside Trailer-Tow Mirrors
If your vehicle is equipped with this style
trailering-type mirror, they can be adjusted so you
can have a clear view of the objects behind you.
Pull out the mirror head to extend it for better
visibility when towing a trailer.
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