Baytopia

This has happened to me about 3 times in the last 4 months that I have had my Q8 Premium Plus. I am driving on the highway using the ACC/Automatic Cruise Control, and without warning or apparent cause, the ACC starts to brake and slow the car down. No other car was in front of me to cause this, and no apparent obstacle. I have to disengage the ACC and set it again. Anyone else experience this?

Tom Peitler

I have seen it. It is a response to it reading a new speed limit sign and the car deciding that that is the speed it needs to go and boom, you brake. I have yet to find the setting to make it stop doing that.

d2000one

I have this issue also and my car is in for service now. I received a call from service stating that my car is ready and that there is a software flash to correct it. If there is a bulletin number or something I will post it.

Baytopia

Thanks for this info.. Very helpful.

SYMAWD

Do you have predictive control on? Having it on will make the car slow for curves and adjust to the speed limit as it changes. Shutting off predictive control will keep the ACC at the set speed.

Baytopia

Excellent - I think I do. I will check. Thanks.

d2000one

Got my Q back yesterday with this resolution: Road tested vehicle, found stored fault B200FF9 internal malfunction control unit for lane change assist - performed SVM flash as per bulletin 2053868/2.

It hasn’t happened again yet. Will keep you all posted.

SoundsoftheSuburbs

I'm too lazy to read my manual. How do I stop the car from slowing down because of a speed limit change? Going less than 5 or 10 over in Chicagoland is going to get me rear-ended.

JeffSmith

I understand a vehicle substituting its driving for yours. But I believe you should be able to turn off (and keep it off) any feature where that happens.

tomk

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