Cruise Control: Description and Operation

2778 - Cruise Control







Cruise control serves to keep the speed of the vehicle constant irrespective of road resistance without requiring the driver to operate the accelerator pedal. The Motronic system implements the speed set by the driver by adjusting the throttle accordingly. The throttle can thereby be adjusted independently of the accelerator position in cruise control mode. Cruise control is active in the speed range from approx. 19 mph (30 km/h) to approx. 149 mph (240 km/h). Cruise control can be used in all gears.

Cruise control is operated by way of a lever on the stalk control. Apart from maintaining the current speed (cruising), cruise control also enables a stored target speed to be approached (Resume function), acceleration and deceleration, increase or reduction of the set speed in small steps (tap up and tap down) and selection of the current vehicle speed as the set speed (Set function).

The speed can be changed in constant steps via the steering column stalk while cruise control is active:
- Per pulse from the control lever as a result of pressing briefly forward +1 mph (2 km/h)
- Per pulse from the control lever as a result of pulling briefly -1 mph (-2 km/h)

Particularly when driving downhill, the vehicle speed can differ from the stored set cruise speed. To enable more effective compliance with the set speed, vehicles equipped with Tiptronic are able to improve the braking effect by initiating a maximum of two downshifts. Downshifting by a maximum of two gears is also effected when only minimum deceleration is attainable by pulling and holding the lever in the direction of the driver when driving downhill, for example.

NOTE: A maximum of ten one-touch operations can be carried out in succession.

A maximum of two downshifts may also be performed when more than three tap down operations are carried out by the driver and the resultant deceleration is inadequate.