Drive Systems; Four-Wheel Drive - GMC Sierra Limited 1500 2019 Owner's Manual

If equipped, on vehicles with a
gasoline engine, to disable or
enable Tow/Haul 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 is
displayed.
On vehicles with a diesel engine,
Tow/Haul Mode Grade Braking can
be enabled or disabled by pressing
the Tow/Haul Mode button. Use the
exhaust brake and Tow/Haul Mode
for maximum grade braking.
See Towing Equipment 0 311.
For other forms of grade braking,
see Automatic Transmission 0 260
and Cruise Control 0 280.

Drive Systems

Four-Wheel Drive

If equipped, four-wheel drive
engages the front axle for extra
traction.
Read the appropriate section for
transfer case operation before
using.
Caution
Do not drive on clean, dry
pavement in 4 and 4 (if
equipped) for an extended period
of time. These conditions may
cause premature wear on the
vehicle s powertrain.
Driving on clean, dry pavement in
4 or 4 may:
Cause a vibration to be felt in
the steering system.
Cause tires to wear faster.
Make the transfer case harder to
shift, and cause it to run noisier.
Driving and Operating
Warning
If equipped with four-wheel drive,
the vehicle will be free to roll if the
transfer case is in N (Neutral),
even when the shift lever is in
P (Park). You or someone else
could be seriously injured. Be
sure the transfer case is in a drive
gear 2 , 4 , or 4
parking brake before placing the
transfer case in N (Neutral). See
Shifting Into Park 0 257.
Caution
Extended high-speed operation in
4 may damage or shorten the
life of the drivetrain.
Engagement noise and bump when
shifting between 4 and 4 or from
N (Neutral), with the engine running,
is normal.
267
or set the