...does anyone know what it is? Trying to enter the set-up mode and see if I can bring up the rearview camera guide/layover lines that my OM says I should have and don't. My MB dealership doesn't seem overly interested in fixing the problem.
Just to close this thread out; apparently there is no manually inputed "engineering code" for the Audio 15. All programming is through the OBDII port. Finally got the MB dealer to check the codes for the radio/rearview camera and they found the incorrect VIN flashed to the camera which caused the issue of no guidelines/overlays with the back up view. Dealer refreshed the camera and guidelines came alive. Issue resolved.