What's the 0513 code mercedes?

If You notice a code 0513 on the dash of Your Mercedes and the vehicle is not starting then that usually means that there is a problem with the immobilizer system. The first thing that You should check is the battery in the key fob, if it is dead it will need to be replaced to work with the immobilizer. If that does not solve the problem then You may need to reset the alarm system following the steps that are listed in the owner's manual depending on the year of Your car. If Your immobilizer has a problem that keeps happening I recommend letting Mercedes take a look at it and replace the immobilizer.