A week ago my s40 started acting up. It would surge like i was giving it gas when i was braking, the temp gauge on the dash would surge up like it was off the charts hot, and when i would pull over thinking its overheating the needle would go to normal and stay there. Now last night it wouldn't start/turn over. I had lights / full power but not even a chick from the starter. Anyone have a clue whats going on?

Could it be the CEM? I had where one low beam went out and was told it was the CEM affecting it. I was planning on replacing it but now this is happening. Please help.