Audi Brake Assist problem/annoyance
 

Recently my brake assist (apologies if that is not the right term) seems to be going off more than usual, and in particular one situation. If a car is making a right turn in front of me while I am approaching, the loud warning tone goes off from what I would consider a bit too far away.

And in particular yesterday, the car for the first time applied the brakes in this situation, almost causing the car behind me to ram me (I heard them slam on the brakes when my brakes suddenly went on).

It seems the radar is not sensing that the car/object in front is moving to the right, and will be out of the way by the time the Q5 gets to that point at the current speed.

Anyone else have this issue?

I feel you pain. Automation in vehicles is out of control.

The Presense Plus system as designed can't tell if the followed vehicle is stopping in your path or departing via a turn. If you get too close, it believes you are in danger of a collision and the Brake Guard feature will engage as you describe until the car in front moves far enough into the turn away from your path (or you swerve away). I've had the chime alert in this situation but only once in 2 years has the Brake Guard engaged.

The right turn warning thing surprised me. It's amazing how our perception of risk changes when we think the car in front is turning.

Also had the brake guard come on when a car in front stopped suddenly. My foot hit the brake at the same time, so it made the brake pedal feel strange. I think it's ok. Let's me know if I'm driving too aggressive.

Yes I agree 100% that the system is very good and certainly very useful.

Also let me clarify - the issue of the car turning right is when, I'd say, over 80% of the car turning in front is out of the path of the car. It's not about a car is attempting to turn right ahead - the car ahead has already turned and is almost entirely out of the path. My Q5 seems to do the chime and potentially brake assist at a further distance in this scenario than in a stopped car scenario. Yeah I know technically that's probably impossible, but again, was just throwing that out there to see if others have experienced the same thing.

The Presense system is probably calibrated to detect even a small vehicle so if the turning car was even only 20% detected, it would react (again not detecting the threat was turning away from your path). Also, the speed differential your car is traveling relative to the followed vehicle when it slows down or stops is also is a determining factor on when a warning chime or Brake assist would engage. There's undoubtedly many algorithms designed into the system and like any programming, there is bound to be some operational compromise, in this case on the side of safety.

Does we have this option in the USA/Canada? I can't find it on audi web sites.

I don't think they call it the Presence Plus anymore - it's the Brake Assist.

Thanks for the clarification. However, I can't find reference to this neither. Does ACC include this functionality?

Yup - don't like it, but I guess overall it's nice to have adaptive cruise.