I got it to work on an ML430, could not connect with an 04 500E (had Mercedes rep come out and do it) and then got it to work on a C55. I have a chamberlin head unit.

I agree that the car needs to be CLOSE when you do it. Pretty frustrating.

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1981 300TD
2005 C55
2004 E500
1999 ML430
1992 400E
1998 C43
2001 SL500
1988 300SEL
1986 190E 16V
1991 190E 2.6