2007 GMC Sierra 1500 Pickup Owner's Manual - Page 258

If the transmission continues to operate above 265°F (130°C), contact your nearest dealer or the GM Roadside Assistance Center. See Roadside Assistance Program on page 644. Notice: If you drive your vehicle with the transmission temperature gage above normal operating range, you can damage the transmission. This could lead to costly repairs that would not be covered by your warranty. Do not drive your vehicle while the transmission temperature gage reading is above normal. See your dealer for service. The following situations can cause the transmission to operate at higher temperatures: • Towing a trailer • Hot outside air temperatures A temporary solution to reduce 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 (Gasoline Engine) on page 617 for the proper transmission maintenance intervals. Malfunction Indicator Lamp Check Engine Light Your vehicle has a computer which monitors operation of the fuel, ignition, and emission control systems. Hauling a large or heavy load Low transmission fluid level High transmission fluid level Restricted air flow to the radiator and the auxiliary transmission oil cooler, if equipped. 258