2017 V40 D4 Cruise Control
 

Hi, just looking for info on my v40 fitted with speed limiter and cruise control. When cruise is set it is fine uphill and on flat but going downhill the car does not slow down to the set speed, on occasions I have found it 8mph higher than the set point. Thinking this was a fault I took it to my dealer as it is still under warranty and they inform me this is normal operation. Every other car I have driven with cruise brakes on a descent and frankly in my opinion this is a safety issue. Anyone experience of this. The dealer said only cars with adaptive cruise actually slow the car on a descent, Incredible if true. Thanks in advance.

2016 v40 with cruise & its the same as yours.

It isn't a safety issue, but how you're using it is.

Cruise control is primarily intended to be used on level surfaces, so what you're experiencing is normal. Using cruise control descending a hill isn't ideal & in the nicest way possible, I'd advise you against using it for this purpose. I personally want full manual control of my car going down a hill.

Yes, cars with adaptive cruise control (not yours) do slow down when descending hills. Although, its not a system that should be totally relied upon either (in my opinion). Its a nice feature to have admittedly, but only in the right circumstances.

Even with the adaptive cruise, it is still slow to react.

On a less steep hill the speed can go up by 3-5mph before the system slowly reacts. Not good if you are in an average speed zone, so I have to manually brake.

On a steeper hill it will keep the speed down and apply the brakes as I can see the brake lights reflecting in road signs at night.

I think they programmed it to be gentle so as not to upset passengers, but it can be caught out in situations where it needs to be more aggressive in maintaining the set speed exactly.