2019 Audi A4 / S4 — Owner's Manual
Within the limits of the system, pre sense city can warn you of impending collisions with vehicles and pedestrians and initiate the applicable braking maneuver if needed. Pre sense city is active at speeds of approximately 6 mph (10 km/h) and higher. A pedestrian warning can occur at speeds up to 50 mph (85 km/h), and vehicle warnings can occur at speeds up to 155 mph (250 km/h). A pre sense city braking maneuver is possible at speeds up to 50 mph (85 km/h).