![background image](/i/gmc/154537/gmc-sierra-2500hd-denali-2015/h/gmc-sierra-2500hd-denali-2015-215.png)
Black plate (36,1)
GMC Sierra Denali Owner Manual (GMNA Localizing-U.S/Canada/Mexico-
7299750) - 2015 - CRC - 6/9/14
9-36
Driving and Operating
when driving on downhill grades by
using the engine and transmission
to slow the vehicle. The first time
the system engages for each
ignition key cycle, a DIC message
will be displayed. See
To disable or enable Normal Mode
Grade Braking within the current
ignition key cycle, press and hold
the Tow/Haul button for
five seconds. When the button is
released, the requested mode
change is made. A DIC message
displays. See
For other forms of grade braking,
see
and
.
Manual Mode
Range Selection Mode
If equipped, Range Selection Mode
helps control the vehicle's
transmission and vehicle speed
while driving downhill or towing a
trailer by letting you select a desired
range of gears.
To use this feature:
1. Move the shift lever to
M (Manual Mode).
2. Press the plus/minus buttons on
the shift lever to select the
desired range of gears for
current driving conditions.
When the shift lever is moved from
D (Drive) to M (Manual Mode), a
number displays next to the M,
indicating the current transmission
range.
This number is the highest gear that
the transmission will command while
operating in M (Manual Mode).
All gears below that number are
available. As driving conditions
change, the transmission can
automatically shift to lower gears.
For example, when M5 is selected,
1 (First) through 5 (Fifth) gears are
automatically shifted by the
transmission, but 6 (Sixth) cannot be
used until the plus/minus button on
the shift lever is used to change to
the range.
In vehicles with gasoline engines,
when the shift lever is moved from
D (Drive) to M (Manual Mode), a
downshift may occur. The gear that
the transmission is operating in
when the shift lever is moved from
D (Drive) to M (Manual Mode)
determines if a downshift occurs.
See the following chart.