2007 GMC Sierra 1500 Pickup Owner's Manual - Page 257

Transmission Temperature Gage 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 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). 257