I have a 2009 C350 that is tripping a dash message on start up that says "Autolamp function inoperative". Looks to me that the radio/flat panel display will not dim at night. Other forums have stated that the message may come on with window wiper issues but I am not having any of that. I have replaced the marble sized sun sensor on top of the dash but NOT the sun sensor attached to the rear view mirror. I am not convinced that's the issue since my auto-wipers work just fine off that same sensor and the auto headlights work just fine as well. (that said, I'm not sure why I even changed the sensor on the dash). I hope this is not a stupid SAM unit issue. Anyone ever heard of this or have some recommendations??? Thanks.