question regarding rear lights on 2012 GL450
 

I'm getting warnings on every light on the rear of the car although it looks like they are all working. The only lights not working are the tag light. I realize that if the readings don't make the computer happy then I'll get the warnings. Would the tag light make them all show up as a fault or do I need new rear tail light assemblies?

I think that there may have been a TSB a few years back for the taillight grounding. I think that MBZ may have even sold a ground kit for those.

The tag lamps will cause that, try checking the circuit and work backwards from there.