GMC SIERRA 2002 Manual page 198

Trans Hot...Idle Engine
If you have an automatic transmission, you have a
-
transmission over temperature display contained in the
message center.
Set the parking brake and place the transmission in
PARK (P). Idle the engine until the message center no
longer displays a message. If idling the engine does not
turn the warning message off after 10 to 15 minutes,
contact your nearest dealer or the GM Roadside
Assistance Center. See "Roadside Assistance" in
the Index.
If this warning message is
displayed, pull the vehicle
off the roadway when it is
safe to do so.
NOTICE:
If you keep driving your vehicle with the
transmission TRANS HOT...IDLE ENGINE
message displayed, you can damage the
transmission. This could lead to costly repairs
that may not be covered under your warranty.
The following situations can cause the transmission to
operate at higher temperatures:
D
Towing a trailer
D
Hot outside air temperatures
D
Hauling a 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.
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