Purchased a used S40 for my daughter. Low beam lights were not working but high beam lights were. Most of the forums I read lead me to believe that the problem was a defective CEM circuit board. Couldn't afford a new CEM, so I ordered a used one from ebay for $65.00. Installed the board in about 15 minutes (unplugged battery; removed necessary panels beneath steering column; removed screws holding CEM; wiggled the CEM half way out; disconnected the plug ins; reinstalled new CEM) and whooooolaaaaa!!!! I have low beam lights....hopes this helps someone...