Verybumpy

Say I'm driving 45mph with ACC on and zero cars in front of me i.e. no car detected in the green ACC indicator symbol.

Now I rapidly approach a stop light with one car already stopped at the lights.

I've yet to have pre-sense apply the brakes. I let it go to a point where I chicken out then slam on the brakes myself.

Is this normal operation? Why doesn't ACC ever detect the stopped car?

nictven

You might want to share the year and the type of options that you have for other members to help.

As far as I know, ACC is good for cruise control. I believe newer ACC could come to complete stop in stop&go traffic. I am not sure if the older ACC (e.g. MY2013) has this. It's because it used to be ACC with braking guard - ACC would disengage if too slow, then braking guard will kick in, but then braking guard also has limitation of speed and deceleration.

Newer model/option seems no longer has braking guard, but has further defined pre-sense front/rear/side, where the pre-sense front could apply braking with some limitation of speed of vehicle.

Feel free to correct me if I am wrong.

superswiss

No, ACC does not detect stationary objects. The system monitors moving objects and reacts if they slow down or come to a stop. For ACC to react to a stopped car ahead of you it first had to see the car moving and come to a stop. This is explained in the owner's manual. ACC is only adaptive cruise control that reacts to slowing cars ahead of you and maintains your speed or can bring the car to a stop if traffic ahead of you comes to a stop and resume once it's moving again, but it's not a system that keeps you from slamming into a wall, parked cars or cars ahead of you that were already stopped when they came in range.

SYMAWD

What year is your A7? In the past, ACC was radar based only and radar doesn't pick up stopped vehicles. New A7s now have a laser scanner which better detects stopped vehicles.

Verybumpy

2014 RS7 with every tech option available.

So the poster above you says stopped obstacles are not detected. You say new vehicles do with laser?

You often see a car ad on TV of a child darting out from parked cars and the car auto-stopping.

I'm just trying to sort out how to tell which Audi's do or don't have this type of feature.

I really thought with ACC on it would be a no-brainer for the car to brake or stop no matter what large'ish object gets in front of the car.

superswiss

Since this is the C7 forum, my response was regarding the C7 and you confirmed that you have indeed a C7. The LIDAR system is something the C8 has. It's part of the new AI system, but it's not actually available in North America. Folks, read the owner's manual once in a while. This is all explained there. Read the section about stationary objects on page 82.

For your convenience:

SYMAWD

Newer Audis and many other manufacturers use a camera to detect stopped vehicles and pedestrians (Audi Pre Sense City). The C7 A7 models use a radar based system (braking guard).