That's definitely a great way to start. Hopefully it doesn't come to this but you might need to go your dealer and have them take a look.It's a very common issue with GM vehicles. In fact if you search "Adaptive Cruise Control is Temporarily Unavailable" on Google a ton of results show up, all from owners like ourselves, of other GM products of course. It might be worth giving those a read. I found a few tips within them.