Hill Descent Control (Hdc) - GMC Sierra Owner's Manual

250 Driving and Operating
If TCS is limiting wheel spin when
pressed, the system will not turn off until
the wheels stop spinning.
To turn off both TCS and StabiliTrak/ESC,
press and hold until the traction off light
and the StabiliTrak/ESC OFF light
come on and stay on in the instrument
cluster, then release. The appropriate
message will display in the DIC.
To turn TCS and StabiliTrak/ESC on again,
press and release . The traction off light
and the StabiliTrak/ESC OFF light
the instrument cluster turn off.
StabiliTrak/ESC will automatically turn on if
the vehicle exceeds 56 km/h (35 mph).
Traction control will remain off.
The vehicle has a Trailer Sway Control (TSC)
feature and a Hill Start Assist (HSA) feature.
See Trailer Sway Control (TSC) 0 292 or
Hill Start Assist (HSA) 0 248.
Adding accessories can affect the vehicle
performance. See Accessories and
Modifications 0 309.

Hill Descent Control (HDC)

is
If equipped, Hill Descent Control (HDC) sets
and maintains vehicle speed while driving
down steep grades in a forward or reverse
gear. The HDC switch is on the center stack,
below the climate controls.
Press to enable or disable HDC. Vehicle
speed must be below 50 km/h (31 mph).
in
When enabled, the HDC light displays on
the instrument cluster.
A blinking HDC light indicates the system is
actively applying the brakes to maintain
vehicle speed. HDC can maintain vehicle
speeds between 1 and 22 km/h (1 and
14 mph) on grades greater than or equal
to 10%.
If HDC is to be used for more than
three minutes or on grades steeper than
25%, the transfer case should be put into
Four-Wheel Drive Low (4 ) to reduce the
possibility of brake overheating.
Noise from the Electronic Brake Control
Module (EBCM) is normal when HDC is
active.
When HDC is activated, the initial HDC
speed is set to the current driving speed.
It can be increased or decreased by pressing
+RES or SET- on the steering wheel, or by
applying the accelerator or brake pedal. This
adjusted speed becomes the new set speed.
HDC will remain enabled between 30 and
60 km/h (19 and 37 mph); however, vehicle
speed cannot be set or maintained in this
range. HDC will automatically disable if the
vehicle speed is above 80 km/h (50 mph) or
above 60 km/h (37 mph) for at least
30 seconds.
must be pressed again to re-enable HDC.
HDC may disable after an extended period
of use. If this happens, HDC will require
time to cool down. The length of time HDC
remains active depends on road conditions,
grade, set speed, vehicle loading, and
outside temperature.
When enabled, if the vehicle speed is above
30 km/h (19 mph) and below 60 km/h
(37 mph), a DIC message will display.