shrly

My 2015 Q3 with standard cruise control doesn't maintain set speed going down hills--any kind of hill! Dealer and Audi customer service can't tell me why. If you have to reset it constantly, what is the use of having it! Anyone else experiencing this problem?

yellowGTS

What are you expecting to happen?

As the car accelerates down the hill, the cruise control is only offering a minimum set speed, it does not regulate a maximum. If you have a radar based cruise control or a system that uses brake assist to regulate speed, then the car will maintain the set speed.

superswiss

Basic cruise control with coast, resume and accelerate features can only control the throttle. It can speed the car up to the desired speed and ease off the throttle if the speed is higher than what's set, however it can't do anything about the car picking up speed on its on going downhill.

Adaptive cruise control on the other hand is capable of applying the brakes and slow down the car, either because it detects the car in front slowing down or you are going downhill and picking up speed.

Doesn't look like adaptive cruise control is an available option for the Q3, though.

uberwgn

The standard cruise control system does brake the car going down hills. It does it way too early, IMO.

shrly

I appreciate finally getting 2 replies but it seems that Audi must have a different definition of cruise control than Mercedes or BMW. This is the first Audi I have owned in a long time. My Mercedes and BMWs, none of which had adaptive cruise control, slowed the vehicle down when I was going down a hill to maintain the set speed. so yellow GTS I was expecting the same with the Audi! And superswiss it certainly seemed that the basic cruise control in those vehicles controlled more than the throttle. My husband and I recently traveled from northern NY to the Atlanta area towing a trailer and his Mercedes GLK with its BASIC cruise control maintained our speed on all kinds on declines!

uberwgn

Well, the Audi maintains your speed +/- 2 mph or something close to that. At least our 3 cars do.


I'm not clear on what you expect to see, shrly. Do you wish the car to continue picking up speed as it rolls down a long hill?


Our 2002 Mercedes regulated the speed when traveling down a long hill but it was something far in excess of 2 mph beyond the set speed. It was probably 8 mph in excess of the set speed before the brakes were applied.

shrly

thank you uberwgn! I just saw your reply. My Q3 doesn't brake at all!

shrly

uberwgn: what I expect to see is the car maintaining the set speed and not suddenly free wheeling down a hill. I believe our GLK maintained the speed about +/- 2 mph as you describe yourAudis doing. I see you have a Q5. Could there be a differnce between the Q3 and the Q5?

uberwgn

Well, maybe the design has changed or you are suffering a software bug.


There's another thing you can check, if you are so inclined. Set the cruise control when you are on a flat road and no cars behind. Push and hold the cruise control stalk down and the car will slow gradually and then it will start to brake quite aggressively. You should be able to see the tail lights come on when you do this.

uberwgn

• "The speed is kept constant by modifying engine power or through an active brake intervention."
• "Please note that unconsciously "resting" your foot on the accelerator pedal causes the cruise control not to brake. This is due to the control system being overridden by the driver's acceleration."
• "The brake lights illuminate as soon as the brakes apply automatically."