GMC Sierra Denali 2017 Owner's Manual page 300

Warning
Using LKA while towing a trailer
or on slippery roads could cause
loss of control of the vehicle and
a crash. Turn the system off.
How the System Works
The LKA camera sensor is on the
windshield ahead of the rearview
mirror.
To turn LKA on and off, press
on the center stack.
A
When on, is green if LKA is
available to assist and provide LDW
alerts. It may assist by gently
turning the steering wheel and
A
display as amber if the vehicle
approaches a detected lane marking
without using a turn signal in that
direction. It may also provide an
A
LDW alert by flashing
as the lane marking is crossed.
Additionally, there will be three
beeps, or the driver seat will pulse
three times, on the right or left,
depending on the lane departure
direction.
The LKA system does not
continuously steer the vehicle.
If LKA does not detect active driver
steering, an alert and chime may be
provided. Move the steering wheel
to dismiss.
When the System Does Not
Seem to Work Properly
The system performance may be
A
affected by:
Close vehicles ahead.
Sudden lighting changes, such
as when driving through tunnels.
Banked roads.
Roads with poor lane markings,
such as two-lane roads.
If the LKA system is not functioning
properly when lane markings are
amber clearly visible, cleaning the
windshield may help.
LKA assistance and/or LDW alerts
may occur due to tar marks,
shadows, cracks in the road,
Driving and Operating
temporary or construction lane
markings, or other road
imperfections. This is normal system
operation; the vehicle does not need
service. Turn LKA off if these
conditions continue.
299