GMC 2007 Sierra - Manual (Page 257)

Transmission Temperature Gage
Your vehicle may have a transmission
temperature gage.
When your ignition is on, the gage shows the
temperature of the transmission fluid. The normal
operating range is from 100°F (38°C) to about
265°F (130°C).
At approximately 265°F (130°C), the Driver
Information Center (DIC) will display a
TRANSMISSION HOT message and the
transmission will enter a transmission protection
mode. When the transmission enters the protection
mode, you may notice a change in the
transmission shifting patterns. The transmission
will return to normal shifting patterns when
the transmission fluid temperature falls below
260°F (125°C).
See Driver Information Center (DIC) on page 265
for further information.
If your vehicle has an Allison ® transmission, and
the fluid reaches temperatures of approximately
275°F (135°C) or greater, the DIC will display
a TRANS HOT IDLE ENGINE warning message
and a chime will sound until the temperature
falls below 265°F (130°C). Pull the vehicle off the
roadway when it is safe to do so. Set the
parking brake, place the transmission in PARK (P)
and allow the engine to idle until the transmission
temperature falls below 265°F (130°C).
United States Canada
257