GMC Sierra Denali 2500HD 2014 Owner's Manual page 266

GMC Sierra Denali 2500HD and 3500HD (GMNA-Localizing-U.S./Canada-
7142957) - 2014 - CRC 1st Edition - 3/28/13
9-32 Driving and Operating
the vehicle is already moving, use
N (Neutral) only. Also, use
N (Neutral) when the vehicle is
being towed.
Warning
Shifting into a drive gear while the
engine is running at high speed is
dangerous. Unless your foot is
firmly on the brake pedal, the
vehicle could move very rapidly.
You could lose control and hit
people or objects. Do not shift
into a drive gear while the engine
is running at high speed.
Notice: Shifting out of P (Park) or
N (Neutral) with the engine
running at high speed may
damage the transmission. The
repairs would not be covered by
the vehicle warranty. Be sure the
engine is not running at high
speed when shifting the vehicle.
D (Drive): This position is for
normal driving. It provides the best
fuel economy for the vehicle. If you
need more power for passing, and
you are:
Going less than about 55 km/h
(35 mph), push the accelerator
pedal about halfway down.
Going about 55 km/h (35 mph) or
more, push the accelerator all
the way down.
D (Drive) can be used when towing
a trailer, carrying a heavy load,
driving on steep hills, or driving
off-road. You may want to shift the
transmission to a lower gear
selection if the transmission shifts
too often.
Downshifting the transmission in
slippery road conditions could result
in skidding; see Skidding under
Loss of Control on page 9-5.
The vehicle has a shift stabilization
feature that adjusts the transmission
shifting to the current driving
conditions in order to reduce rapid
Black plate (32,1)
upshifts and downshifts. This shift
stabilization feature is designed to
determine, before making an
upshift, if the engine will be able to
maintain vehicle speed by analyzing
things such as throttle position,
vehicle load, and hill grade. If the
shift stabilization feature determines
that a current vehicle speed cannot
be maintained, the transmission
does not upshift and instead holds
the current gear. In some cases, this
may appear to be a delayed shift,
however the transmission is
operating normally.
The vehicle's transmission uses
adaptive shift controls. Adaptive
shift controls continually compare
key shift parameters to
pre-programmed ideal shift
conditions stored in the
transmission's computer. The
transmission constantly makes
adjustments to improve vehicle
performance according to the way
the vehicle is being used, such as
with a heavy load. During this
adaptive shift controls process,