What does it mean when the service stabili trak and engine power reduce lights come on? This typically happens when turning or going up a hill. The car will slow down or even stop. How expensive is this to fix?

 

I know this post is old but I just seen this and thought I would share my experience with this. We have a 2013 also. I have never had this issue going uphill. We have seen this a few times. It does this by default for anything that goes wrong to prevent further damage to the engine. The times it happened to us was faulty alternator/battery and most recently a failing valve spring.