No, the system noticed that something was not right and shows that by illuminating the light. The SRS system will function properly though (if it IS a seat belt problem).
If you go to the MB dealer with your car, they can check what fault was noticed by the SRS system.
I have replaced one of the seat belt buckles in my 300SL because of the illuminated SRS light (but still no SRS related seat belt buckles in my W202 C class!).
with a minor 600+k