BMW Repair: Unknown light, rear view mirror, bmw assist

Question
I have a 2004 325ci.  I recently started to see a green LED on my rear view mirror start to light up and flicker.  It is right next to the SOS button on lower right corner of the mirror.  I took it to the dealer and it wasnt doing it for them when the car was in their possession.  Within an hour of leaving it started to do it again.  Why is this light coming on?  I was told it had something to do with the BMW Assist but i do not subscribe to the membership. It is intermittent, if i drive the car four times in the day it may flicker and come on for two of the rides.  

Answer
Joesph, The LED is for the Telematics control unit in your car. It should come on (2 sec.)when you first turn the key on for a few seconds for a bulb/system check. It should also light up if you press the SOS button. I have never had a complaint of it comming on intermittently while driving. Since you dont have an active BMW service subcription there is nothing to worry about. The TCU is most likely at fault. I have seen TCU LED faults in hundreds of vehicles control unit TCU memorys when checking for faults. BMW states that most of these faults are erronious. Leave the vehicle with the dealer if it really bothers you and tell them to keep until they find a solution or a specific reponse or fix from BMW technical on this issue. This may take a while because BMW is loosing their a** on these TCU's from motorola and Techs are almost restricted from replacing them.
-Evan
-Evan