I am not sure which one you are describing, since you brought up cruise control:
Hill Descent Control (HDC) If equipped, HDC can be used when driving downhill. It sets and maintains vehicle speed while descending a very steep incline in a forward or reverse gear. The HDC switch is on the center stack, below the climate controls. Press 5 to enable or disable HDC. Vehicle speed must be below 50 km/h (31 mph). The HDC light displays on the instrument cluster when enabled. HDC can maintain vehicle speeds between 3 and 22 km/h (2 and 14 mph) on an incline greater than or equal to a 10% grade. A blinking HDC light indicates the system is actively applying the brakes to maintain vehicle speed. When HDC is activated, the initial HDC speed is set to the current driving speed. It can be increased or decreased by pressing the +RES or SET- steering wheel controls or by applying the accelerator or brake pedal. This adjusted speed becomes the new set speed. HDC will remain enabled between 22 and 60 km/h (14 and 37 mph); however vehicle speed cannot be set or maintained in this range. It will automatically disable if the vehicle speed is above 80 km/h (50 mph) or above 60 km/h (37 mph) for at least 30 seconds. 5 must be pressed again to re-enable HDC. When enabled, if the vehicle is at a speed above 22 km/h (14 mph) and less than 60 km/h (37 mph), a DIC message will display. See Vehicle Speed Messages 0 164.
Normal Mode Grade Braking If equipped with a gasoline engine and an automatic transmission, Normal Mode Grade Braking is enabled when the vehicle is started, but is not enabled in Range Selection Mode. It assists in maintaining desired vehicle speeds when driving on downhill grades by using the engine and transmission to slow the vehicle. The first time the system engages for each ignition key cycle, a DIC message will be displayed. See Transmission Messages 0 162. To disable or enable Normal Mode Grade Braking within the current ignition key cycle, press and hold the Tow/Haul button for five seconds. When the button is released, the requested mode change is made. A DIC message displays. See Transmission Messages 0 162. For other forms of grade braking, see Tow/Haul Mode 0 295 and Cruise Control 0 311.