As far as I am aware, you can only read internal fault codes for the instrument ECU that way, I know loads who have tried and failed to get any fault codes that mean anything out of them! 
I have never tried myself, never needed to as I have the BMW tool, but I would be VERY surprised if it was possible as I cant see any reason for BMW to put the software into the instrument ECU for this function as it would not benefit them and would only serve to help us independants... and no car manufacturer is guilty of that charge!!!
I have never tried myself, never needed to as I have the BMW tool, but I would be VERY surprised if it was possible as I cant see any reason for BMW to put the software into the instrument ECU for this function as it would not benefit them and would only serve to help us independants... and no car manufacturer is guilty of that charge!!!