GMC 2001 Yukon XL Owner's Manual page 101

NOTICE:
If your rear wheels can't rotate, don't try to
drive. This might happen if you were stuck in
very deep sand or mud or were up against a solid
object. You could damage your transmission.
Also, if you stop when going uphill, don't hold
your vehicle there with only the accelerator
pedal. This could overheat and damage the
transmission. Use your brakes or shift into
PARK (P) to hold your vehicle in position
on a hill.
On cold days, approximately 32 _ F (0 _ C) or colder, your
transmission is designed to shift differently until the
engine reaches normal operating temperature. This is
intended to improve heater performance.
Tow/Haul Mode Selector Switch
Your vehicle is equipped with a tow/haul mode. The
selector switch is located on the end of the column shift
lever. You can use this feature to assist when towing or
hauling a heavy load. See "Tow/Haul Mode" in the
Index for more information.
The tow/haul mode also interacts with the Autoride t
feature, if your vehicle is so equipped, to enhance
the ride when trailering or with a loaded vehicle.
See "Autoride t " in the Index.
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