Sorry to re-ignite an old thread, but you have just described EXACTLY the problem we have had. We had a Scala. It did EXACTLY the problem you describe. Cruise control felt like it was repeatedly pressing the brake peddle and the gear indicator would continually make crazy recommendations between 5th and 6th, then recommend 1st, 2nd at 60mph. It was repaired, but still did it to some degree. We changed it for a Kamiq and on the first outing, an SOS warning came onto the dash board and the cruise control has failed. The Kamiq is with the garage and we have a different Kamiq for a loan car. Again, first trip out, it's like being back in the Scala, the cruise control feels like it is repeatedly pressing the brake peddle while you are driving. None of these vehicles have ACC.
Surely we can't be the unluckiest customers in the world to get multiple vehicles which all have the same problem???
any ideas?