Hi Mike,---- Yes ,it is the small circuit board inside the relay. Once you remove the relay cover by sliding 2 small screwdrivers along the 2 release tabs, the cover will pop off. Circuit board is attached at right angle to base containing the male pins. If you have the patients & soldering skills with a small soldering iron ,it's a piece of cake job,& will save you some bucks, you won't have to replace the relay. I have been an electronic technician for over 40 years , sorry to say not at a Mercedes Shop. Own 2 Benz only because I can tinker with them, now that I am retired. Let me know if you need more help. Ray