Cadillac 2011 DTS Owner's Manual page 183

IntelliBeam only activates the high-beams when driving
over 20 mph (32 km/h).
The high-beam headlamps remain on, under the
automatic control of IntelliBeam, until any of the
following situations occur:
The system detects an approaching vehicle's
headlamps.
The system detects a preceding vehicle's
taillamps.
The outside light is bright enough that high-beam
headlamps are not required.
The vehicle's speed drops below 15 mph
(24 km/h).
The headlamp stalk is moved forward to the
high-beam position or the flash-to-pass feature is
used. See Headlamp High/Low-Beam Changer on
page 4 6 and Flash-to-Pass on page 4 10.
When either of these conditions occur, the
IntelliBeam feature is disabled and the IntelliBeam
light in the mirror turns off until the high-beam stalk
is returned to the neutral position.
If IntelliBeam was using low-beams prior to this
action, the IntelliBeam feature is temporarily
disabled until the stalk is returned to the neutral
position.
The exterior lamp control is turned to any setting
except AUTO.
When this occurs, IntelliBeam is disabled until the
control is turned back to the AUTO position.
The IntelliBeam system is turned off at the inside
rearview mirror.
IntelliBeam might not turn off the high-beams if the
system cannot detect other vehicle's lamps because of
any of the following:
The other vehicle's lamp(s) are missing, damaged,
obstructed from view, or otherwise undetected.
The other vehicle's lamp(s) are covered with dirt,
snow, and/or road spray.
The other vehicle's lamp(s) cannot be detected
due to dense exhaust, smoke, fog, snow, road
spray, mist, or other airborne obstructions.
Your vehicle's windshield is dirty, cracked,
or obstructed by something that blocks the view of
the IntelliBeam light sensor.
Your vehicle's windshield is covered with ice, dirt,
haze, or other obstructions.
Your vehicle is loaded such that the front end of
the vehicle points upward, causing the IntelliBeam
sensor to aim high and not detect headlamps and
taillamps.
You are driving on winding or hilly roads.
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