2009 GMC Sierra 1500 Crew Cab Owner's Manual - Page 395

Tow/Haul Mode Pressing this button at the end of the shift lever turns on and off the tow/haul mode. Tow/Haul is designed to be most effective when the vehicle and trailer combined weight is at least 75 percent of the vehicle's Gross Combined Weight Rating (GCWR). See "Weight of the Trailer" later in the section. Tow/Haul is most useful under the following driving conditions: • When pulling a heavy trailer or a large or heavy load through rolling terrain. • When pulling a heavy trailer or a large or heavy load in stop and go traffic. • When pulling a heavy trailer or a large or heavy load in busy parking lots where improved low speed control of the vehicle is desired. This indicator light on the instrument panel cluster comes on when the tow/haul mode is on. Operating the vehicle in Tow/Haul when lightly loaded or with no trailer at all will not cause damage. However, there is no benefit to the selection of Tow/Haul when the vehicle is unloaded. Such a selection when unloaded may result in unpleasant engine and transmission driving characteristics and reduced fuel economy. Tow/Haul is recommended only when pulling a heavy trailer or a large or heavy load. Tow/Haul is a feature that assists when pulling a heavy trailer or a large or heavy load. See Tow/Haul Mode on page 2-34 for more information. 4-69