Wrong parameter means you're not using the SLK320 model. As far as the seat belt tensioner/ retractor , the code I found (P1018) on the Actron site said that's what its tied to. On our cars , It runs into the ORC which acts as readiness for the SRS an that lights the airbag light, which is on , on your dash..correct. Good luck...

FYI , neither one of those codes are listed in our service manuals. Ala_Xfire found an answer , I found an answer , hope you find an answer that works.