Hi, my name is***** your mechanic automotive expert, and I will be happy to assist you today. In some cases, I may need more information to assist better. I apologize for any delay.
I try to be here most weekdays and some weekends. If you respond and I do not respond back right away I will do so as soon as I can.
Dear customer, if the sliding door when closing does not lock, it surely is a problem in the lock system, the lock system of this Mercedes is very simple, it is simply a hook on the door that fits another hook on the body, as well that the failure can be in 1 of these two factors.
The first one can be a problem in the bodywork hook, it is very easy to verify it because it is right where the door closes, it is a hook that sometimes cannot fit well or keep its position when closing the doors
Second is that the door lock system, that is, the door hook has a problem, due to both opening and closing the door and the door cannot make the lock hook open and close normally, therefore the door does not finish closing.
These systems are not easy to verify but I recommend you to not necessarily go to a Mercedes dealership. Any auto locksmith works with this locksmith system and can do the job at a lower cost than it can cost you in the dealership.
In the worst cases, the lock system is replaced.
Do you understand me, dear customer?
My goal is to give you the best advise i can, therefore please do not doubt to ask if you have any doubt or if there is anything else i can help you with.
Kind regards, Sebastian.