UK-POLOS.NET - THE VW Polo Forum

So after having had two faulty windscreens I have an issue with my cruise control. Just before first service it stopped working then was fine after restarting the car. Luckily was on a quiet dual carriageway as didn't notice the car slow down at first and there was no warning bong. Dealership serviced the car and checked the cruise saying nothing was wrong.

Same thing happened this morning but going round the M60. Both times it's happened after I've pressed set and then minus (I wanted to drop to 50 from 54 as it's 50 on the M60). Has anyone else experienced any issues with theirs? I have to say that after the bullet proof reliability of my golf I'm very disappointed with my polo so far and I'm getting sick of taking it into the dealer.

I don't understand from your post what the symptoms of the faulty cruise control are. However I have noticed myself that the cruise control acts strange sometimes when rapidly pressing minus after pressing set (which are the same button). If I am at 100 (km/h) and want to go down to 90, I press minus several times, and the target speed goes down but suddenly goes back up again. Like 100 -> 99 -> 98 -> 97 -> 96 -> 95 -> 98 or something like that. My theory is that if you press minus repeatedly faster than the car slows down, the difference between target speed and instantaneous actual speed becomes too large. If you then press the minus button again, the system doesn't interpret it as "minus", but as "set". So it sets your current speed as a new target speed. The solution is to not decrease the target speed too fast.

I don't know if this is your problem, but this is what I found.

The symptoms are that I press set and it sometimes just stops working completely. The warning symbol comes up to take it to a technician and I can't use the cruise control until the car has been restarted. I've also found it tends to happen just as yours does, if you press minus quickly. Think it's just a design fault as it's working again now (touchwood).