2001 GMC Sierra 1500 Pickup Owner's Manual - Page 280

D Then, during the first 500 miles (800 km) that you Tow/Haul Mode (If Equipped) Tow/haul is a feature on automatic transmission equipped vehicles that assists when pulling a heavy trailer or a large or heavy load. The purpose of the tow/haul mode is to: tow a trailer, don't drive over 50 mph (80 km/h) and don't make starts at full throttle. This helps your engine and other parts of your vehicle wear in at the heavier loads. tow in DRIVE (D). You may want to shift the transmission to THIRD (3) or, if necessary, a lower gear selection if the transmission shifts too often (e.g., under heavy loads and/or hilly conditions). If you have a manual transmission and you are towing a trailer, it's better not to use FIFTH (5) gear. Just drive in FOURTH (4) gear (or, as you need to, a lower gear). See "Tow/Haul Mode" in the Index. D If you have an automatic transmission, you can D Reduce the frequency and improve the predictability of transmission shifts when pulling a heavy trailer or a large or heavy load. heavy trailer or a large or heavy load as when the vehicle is unloaded. less throttle pedal activity when pulling a heavy trailer or a large or heavy load. D Provide the same solid shift feel when pulling a D Improve control of vehicle speed while requiring Automatic transmission equipped vehicles are provided with a button at the end of the shift lever which when pressed enables tow/haul. When the button is pressed, a light on the instrument panel will illuminate to indicate that tow/haul has been selected. Tow/haul may be turned off by pressing the button again, at which time the indicator light on the instrument panel will turn off. The vehicle will automatically turn off tow/haul every time it is started. Three important considerations have to do with weight: D the weight of the trailer, D the weight of the trailer tongue D and the weight on your vehicle's tires. 4-58