GMC 2012 Terrain Owner's Manual page 259

When the vehicle crosses a
detected lane marking, the LDW
indicator will flash and three beeps
will sound. LDW will not warn if the
turn signal is on or if a sharp
maneuver is made.
How the System Works
The LDW camera sensor is on the
windshield ahead of the rearview
mirror.
To turn LDW on and off, press the
LANE DEPART control on the
steering wheel. The control indicator
will light when LDW is on.
I n f o r ma t i o n P r o v i d e d b y :
Driving and Operating
When the vehicle is started, the
LDW indicator on the instrument
panel will come on briefly.
LDW operates at speeds of 56 km
(35 mph) or greater. If LDW is on,
the LDW indicator will appear green
if the system detects a left or right
lane marking. This indicator will
change to amber, flash, and three
beeps will sound if the vehicle
crosses a detected lane marking
without using the turn signal.
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