GMC YUKON XL 2003 Manual page 116

If you manually select SECOND (2) in a light duty
automatic transmission, the transmission will drive in
second gear. You may use this feature for reducing the
speed of the rear wheels when you are trying to start
your vehicle from a stop on slippery road surfaces.
FIRST (1): This position gives you even more power
(but lower fuel economy) than SECOND (2). You
can use it on very steep hills, or in deep snow or mud.
If the shift lever is put in FIRST (1) while the vehicle
is moving forward, the transmission won't shift into first
gear until the vehicle is going slowly enough.
Nofice:
If your rear wheels won't turn, 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 (OOC) 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
Your vehicle may be equipped with a tow/haul mode. If
so, the selector button 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 Towing
a
Trailer
on page 4-59 for more information.
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