Range Selection Mode
Range Selection Mode helps control the vehicle's transmission and vehicle speed while driving downhill or towing a trailer by letting you select a desired range of gears.
To use this feature:
Move the shift lever to L (Manual Mode).
Press the plus/minus buttons on the shift lever to select the desired range of gears for current driving conditions.
When the shift lever is moved from D (Drive) to L (Manual Mode), a number displays next to the L, indicating the current transmission range.
This number is the highest gear that the transmission will command while operating in L (Manual Mode). All gears below that number are available. As driving conditions change, the transmission can automatically shift to lower gears. For example, when L5 is selected, 1 (First) through 5 (Fifth) gears are automatically shifted by the transmission, but 6 (Sixth) cannot be used until the plus/minus button on the shift lever is used to change to the range.
When the shift lever is moved from D (Drive) to L (Manual Mode), a downshift may occur. The gear that the transmission is operating in when the shift lever is moved from D (Drive) to L (Manual Mode) determines if a downshift occurs. See the following charts.
6-Speed Automatic Transmission
8-Speed Automatic Transmission
10-Speed Automatic Transmission
Grade Braking is not available when Range Selection Mode is active. See Tow/Haul Mode.
While using Range Selection Mode, cruise control and the Tow/Haul Mode can be used.
If the vehicle has an exhaust brake, it can also be used, but will not automatically downshift the transmission. See “Exhaust Brake” in the Duramax diesel supplement.
Caution
Spinning the tires or holding the vehicle in one place on a hill using only the accelerator pedal may damage the transmission. The repair will not be covered by the vehicle warranty. If the vehicle is stuck, do not spin the tires. When stopping on a hill, use the brakes to hold the vehicle in place.
Low Traction Mode
If equipped, Low Traction Mode assists in vehicle acceleration when road conditions are slippery, such as with ice or snow. While the vehicle is at a stop, select L2 using Range Selection Mode. This will limit torque to the wheels and help prevent the tires from spinning.
To adjust each mirror:
Press or to select the driver or passenger side mirror. The indicator light will illuminate.