GMC Terrain: Roof / Automatic Reversal System
The sunroof has an automatic
reversal system that is only active
when the sunroof is operated in
express-close mode.
If an object is in the path while
express closing, the reversal system
will detect an object, stop, and open
the sunroof again.
If frost or other conditions prevent
closing, override the feature by
closing the sunroof in manual mode.
To stop movement, release the
switch.

Dirt and debris may collect on the
sunroof seal or in the track. This
could cause an issue with sunroof
operation or noise. It could also plug
the water drainage system.
Periodically open the sunroof and
remove any obstacles or loose
debris. Wipe the sunroof seal and
roof sealing area using a clean
cloth, mild soap, and water. Do not
remove grease from the sunroof.
If water is seen dripping into the
water drainage system, this is
normal.
Sunroof Switch
Sunshade Switch
If equipped, the sunroof only
operates when the ignition is on or
in ACC/ACCESSORY, or when
Retained Accessory Power (RAP) is
active...
Other information:
For information on the Tow/Haul
Mode, see Driver Mode Control.
Automatic Engine Grade Braking
Automatic Engine Grade Braking
assists when driving downhill.
It maintains vehicle speed by
automatically implementing a shift
pattern that uses the engine and the
transmission to slow the vehicle.
The system will automatically
command downshifts to reduce
vehicle speed. The normal shift
pattern..
The charging system light comes on
briefly when the ignition is turned
on, but the engine is not running, as
a check to show the light is working.
The light turns off when the engine
is started. If it does not, have the
vehicle serviced by your dealer.
If the light stays on, or comes on
while driving, there may be a
problem with the electrical charging
system. Have it checked by your
de..