Cruise Control Malfunctioning (i Nearly Had An Accident)

[ChesterD]

I've had my T6 just three weeks. Finally got to go on a proper drive (1600 km) and I experienced problems with the Cruise Control. Occasionally when tapping the cruise control down it would jump back up anywhere from 2km to 10km more. I could never replicate it so not sure what is causing it. I would say that for every 20 occasions I tap the speed down it randomly jumps back up. At one stage I was tapping down to 50km/h when it jumped from about 52 up to 62. It gave me such a shock I was disorientated and nearly back ended the car in front (of course the car in front of the car in front chose that moment to stop suddenly for no apparent reason before doing a u-turn).

I do not have cruise control on the steering wheel. It's not adaptive cruise control.

I figure I just need to book it in but any thoughts appreciated. I figure they will not be able to replicate it... Other than this the car seems to have no issues.

 

[mmi]

My theory is the following for the controls on the stalk:
The button down has actually two functions 1) set cruise control speed 2) but when cruising at set speed - decelerate by 1 mph/kmh.
So if you are over the previously set speed it actually locks the now current speed into CC thus actually jumping up.

 

[ChesterD]

Okay thanks that makes sense. Giving two functions to one button seems like asking for trouble. This is my first modern car (my last car was a Volvo from 1989) so getting used to the way modern cars work is a work in progress... When it jumped up from 52 to 62 it did seems to suddenly speed up but maybe I just imagined it...

 

[mmi]

When it jumped up from 52 to 62 it did seems to suddenly speed up but maybe I just imagined it...

Glad to hear if that makes sense. It might actually speed up a bit as when you "set" the speed while the van is decelerating so before the functionality kicks in you are already a bit below set speed thus needing to speed up. Similar effect as when using CC on road with short steep'ish uphills and downhills. On certain conditions the CC lags just before the top of the hill and then for a moment overshoots over the hilltop.

 

[ChesterD]

Yeah I guess I need to realise that it's not perfect and not to expect it to work perfectly under all conditions!