the key fob for my '97 E320 went through the washing machine. Found it just before wife started the dryer. I took it apart and dried it with a hair dryer. Put in new batteries as the originals appeared to be damaged. Went thru the re-sync procedure in the owner's manual amd all is fine now. Pay careful attentinon as you disassemble the case. Mine has a tricky little spring to make the key extend when a putton on the fob is punched. You have to put that back just so and actually wind the spring a couple of turns before putting the case together.