GMC 2001 Yukon XL Owner's Manual page 154

The following situations can cause the transmission to
operate at higher temperatures:
D
Towing a trailer
D
Hot outside air temperatures
D
Hauling a large or heavy load
D
Low transmission fluid level
D
High transmission fluid level
D
Restricted air flow to the radiator and the auxiliary
transmission oil cooler (if equipped).
A temporary solution to hotter transmission operating
temperatures may be to let the transmission cool down.
If the transmission is operated at higher temperatures on
a frequent basis, see "Scheduled Maintenance" in the
Index for the proper transmission maintenance intervals.
2-76
Low Traction Light (If Equipped)
You may feel or hear the system working or notice a
lack of accelerator response, but this is normal.
The LOW TRACTION light also comes on briefly when
you turn your ignition to RUN. If the light doesn't come
on then, the system may require service; have it fixed so
it will be there to tell you when the Traction Assist
System is active. Slippery road conditions may exist if
the LOW TRACTION light comes on, so adjust your
driving accordingly.
If you have the Traction
Assist System, this light
will come on when the
system is limiting wheel
spin. See "Traction Assist
System" in the Index.