Downhill speed control is activated on a downhill gradient when the selector lever is in D/S and the driver presses the brake pedal. The gearbox automatically selects a suitable gear for the gradient. The downhill speed control function attempts to maintain the speed at which the vehicle was travelling when the foot brake was applied (subject to the laws of physics and technical limitations of the power train). It may be necessary to adjust the speed again using the foot brake. The downhill speed control can change down to 3rd gear but no further, so it may be necessary to change to tiptronic mode on very steep gradients. In this case, change down manually to 2nd or 1st gear in tiptronic mode to use the engine braking effect and reduce the load on the brakes.

Downhill speed control is deactivated as soon as the road levels out again or you press the accelerator pedal.

On vehicles with cruise control system^* link► , downhill speed control is activated when you set a cruising speed.