So today the passenger side headlight went out. Its not the bulb nor the fuse so I'm assuming its the CEM. My passenger window has also not been working. (I have to move the passenger door panel until it works.) Should I wait and buy a used CEM from a car the same year as mine? Or should get a headlight relay from a 2001 s40 CEM and swap the old one? Can I do that? Are there any vendors where I can buy the relay itself in the US.

 

I believe the CEM is the same part number for 00 to 04 S40s. You can probably find a used CEM on eBay or use car-part.com to find a yard that has some Gen 1 S40s. The CEM is right above the hood release and is not paired to the car so you can swap out easily. I think I paid $65 for a used CEM when I lost the low beams on my '00 S40