Volvo Repair: timing belt change on a 2000 volvo s40, volvo mechanics, 2000 volvo s40

Question
what are the correct steps to changing the timing belt on a Volvo s40 year 2000. I had a non Volvo mechanic change the belt and now we get a check engine code that wont clear. something with the crankshaft and camshaft sensor. i heard that a vvt needs to be reset. what is that.  thanks

Answer
Cedric, thats what happens when non Volvo mechanics try to put these belts on.  He put the belt on wrong so it has to be redone.  The 2 cams have to be lined up with the top marks on the belt cover and the crank mark.  The exhaust cam will want to move to the left after the belt is removed. All marks MUST be dead on or this is what happens.  What is a WT?  I have no idea. Never heard of such a thing.  Roger