snagitseven

I'm not sure that's correct? At least in my A6, the Presense front works without the ACC having to be engaged so long as the brake guard is turned on in the MMI settings.

baltfan

I took this as meaning that you can effectively of the Presense system by engaging the ACC at all times. I definitely have had it stop my car at speeds over 60 mph for a vehicle stopped in front of me. The caveat to this is that it isn't perfect and there are times where it seems to be late in detecting a stopped vehicle. Perhaps it would have stopped but I didn't want to risk it.

Here is the full section from CR.

"A forward-collision warning and automatic emergency braking system comes standard across the Q7 line. The system, called "pre sense city," scans the road for other cars and pedestrians; it can apply full braking at up to 25 mph and avoid a collision. Above that speed threshold and under 52 mph, the system will slow down the vehicle to mitigate the damage.

One quibble: When the forward collision warning goes off, there is a loud audible warning and the instrument cluster displays "Audi pre assist." It really should say "Brake" rather than displaying branding for an arcanely-named safety system.

Adding on the Driver Assistance package to the two upper trimlines will get you a handful of safety features, including pre sense plus, adaptive cruise control, active lane assist, high-beam assist, and traffic sign recognition.

We like pre sense since it gets you a high-speed forward-collision warning and automatic emergency braking up to approximately 130 mph. A precautionary note: The adaptive cruise control has to be on for this system to work. So it is best to keep the ACC stalk in the On position at all times."

DirkM

I have ACC on most all the time but not active. This way all systems are working and a quick push of the SET button enables cruise control to regulate speed and distance. I haven't experienced a situation in the A4 B9 yet though where pre-sense takes over. In my A6 C7 I was in a situation once where braking guard took over without ACC being active.