Lincoln MKS Owner's Manual page 209

Zone coverage also decreases when parking at shallow angles. Here, the
left sensor is mostly obstructed; zone coverage on that side is severely
limited.
System Lights and Messages
Note: The alert indicator dims when the headlamp switch is not in the
off position and nighttime darkness is detected.
CTA also sounds a series of tones and a message appears in the
information display indicating a vehicle is coming from the right or left.
CTA works with the reverse sensing system which sounds its own series
of tones; see the Parking Aids chapter.
2013 MKS (mks)
Owners Guide gf, 2nd Printing
USA (fus)
Driving Aids
The BLIS and CTA systems
illuminate a yellow alert indicator in
the outside mirror on the side of
the vehicle the approaching vehicle
is coming from.
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