Hummer 2003 H2 Owner's Manual page 170

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.
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.
2-88
TRAC OFF Light
Adjust your driving accordingly. See "Traction Control
System (TCS)" in the Index.
If the TCS detects that the vehicle's brakes are
overheating, the TCS will shut off and the TRAC OFF
light will come on. When the brakes cool off, the TCS
will turn back on automatically and the TRAC OFF light
will go out.
The TRAC OFF light
will come on when a
Traction Control System,
-
Anti Lock Brake System
-
or engine related problem
has been detected and the
vehicle needs service.