Our MANs always seem to display “Trl brake lamp failure” every time they are connected to our skellys. Must be a compatibility issue. 
Also, when you check the oil on the screen, the actual level is only displayed when it’s getting low (only shows the bar with the “OK” in the middle at all other times).
Have you been getting the service reminder for a while? Maybe they forgot to reset it. Otherwise, don’t worry about it unless you see flames or hear a big bang! 