Braking- A Weird One

[Iain]

Quick one;

Its only happened twice, but freaked me out - went to brake - not too hard, and car seemed to go into Shi1tting itself mode and seemed to brake (pedal moved too) into emergency braking mode for a split second; very inarticulately put - when I depressed the break pedal, the car applied considerable more breaking then the force I was applying.

Just wondering WTF it could be.

[anth8910]

Do you have brake assist?
Pro

[Iain]

God knows - where would I find that out? Has Dynamic pack on it, no ACC

[anth8910]

Was there a car turning off in front of you?
Pro

[anth8910]

I have pre sense plus on mine which can trigger the brakes if your approaching a car turning off the road at speed and the car thinks your going to collide with it.
Pro

[wildbore]

Mine does that occasionally. The system is seeing an impending impact that isn't there. I just modulate the pedal and the car recovers pretty quickly.

I do think the Audi software is a little over-zealous. I thought you could turn the feature off in the MMI, though.

Once in my MB, I was braking as i approached a roundabout and the car implemented a complete non-stoppable emergency stop entirely on its own. Now that was frightening...

[Iain]

On both occasions, I was kind of coming up rather quickly on a stationery car..... that might explain it as I wasn't that far behind when it decided to try and put me through the windscreen.

[MartayMcFly]

If you brake quite sharply then back off almost immediately (as in if you react a little too quickly to a car that's not actually in your way), the car sometimes thinks you died or something and keeps braking harder for a second after you back off.

[anth8910]

If you brake quite sharply then back off almost immediately (as in if you react a little too quickly to a car that's not actually in your way), the car sometimes thinks you died or something and keeps braking harder for a second after you back off.

Would be better if it drove you to the nearest A&E or funeral parlour depending on how far gone you are
Pro

[Iain]

Was there a car turning off in front of you?
Pro

Came around a right hand bend to find a stationary queue of traffic - passenger broke into fluent French - and she's Welsh!!!!

[ImmortanJon]

Not alone. I have experienced something similar also. C7 FL with none of the assistance packs other than Pre-Sense Basic Networking.

It's very occasional but on application of very gentle braking force, the brake response is very strong ....not full-on, but a lot more than the control input demanded. It's quite noticeable to passengers also. It's momentary and with further application of the brake, the braking become more linear/normal. Odd !

I meant to post this question to the forum a while back but forgot. At least I know I am not the only one.

[RSVI]

Mine saved me (maybe) when a car pulled in to the lane I was traveling. I was probably doing 30-40 mph more than the car pulling into my lane, the car broke before i had time to react.
Made me jump, it was the first time experiencing active braking. Thought about it afterwards and was rather impressed.

Cars got ACC. You can turn active braking off from within the MMI, but you gotta love ACC on the long busy motorway journeys.

[MikeFish]

There's 2 different braking system being talked about here.
The 1st one is brake assist. This system will apply the brakes at full braking if it thinks you are trying to perform an emergency brake ie you are trying to stop quickly but are not using the brakes to their maximum. I would have thought this was a standard feature on most Audis nowadays if not all of them.
Then there is braking guard which comes as part of the assistance package (ie adaptive cruise control). This will flash. A red car symbol on the dashboard if you are too close to the car in front. It will also prepare the brakes for activation by priming the system and putting the pads right up to the disc but without actually braking. If you get too close it will apply the brakes sharply and make a loud beep and flash another warning on the dash. This can happen accidentally on tightly curved roads when there is a car next to you in the outside lane or on roundabout etc when you are not travelling straight forward. This is very obvious when it happens.

I think the sensation most of you are describing above is the brake assist cutting in to assist you braking unnecessarily. I get this when coming to a stop quickly, it just applies the brakes a bit harder than normal for a split second and no warning on the dash. If you have ACC and get a big warning and noise then it is the braking guard kicking but you'll know about this when it happens.

The braking guard can be turned off via MMI. Not sure about brake assist, I don't recall an option for it in MMI but when you turn ESC off it says one of the brake assist type system is disabled so that might do the trick.

[HDPete]

Something I've not quite understood or been brace enough to test is: if you've got ACC fitted but not active, i.e. Driving normally, if an event catches you off guard and you don't have time to react, will the car brake itself to avoid a collision? (E.g. A car pulling immediately in front of you from a side road or near side lane.

Does lane assist also make any avoiding steering input, if active?

Does Acc also protect against deer / side emerging objects?

[MikeFish]

Even with ACC off your Braking Guard is still active assuming you haven't turn it off via the MMI. I've had it come on a number of times in particular when approaching stationary traffic at an s bend in the road and the car thinks I am going to go straight ahead into the stationary cars when in fact I steer around them following the lanes in the road (but getting close to them).

Lane assist will not steer you away from an accident, I assume as this could potentially put you into mor danger.

I don't believe ACC will protect against side emerging object until they are physically in front of you. This would stop it applying emergency brakes when you are driving past a side road and a car is pulling up to the give way. I imagine it behaves the same as when someone changes lane right into your path and the car applies the brakes.