I cant lock my car with my key .

What is your question?

I have a Mercedes A class w168 of 2001 , and i have to lock it manually by pressing down all 3 door locks and when i step out i have to lock my driver door with the key , so the key unlocks all 4 doors but locks only my door (the driver door), it doesnt lock the boot . The remote signal in key fob it doesnt work , i changed the batteries but still doesnt work. There is a way to lock all car , is by closing all doors except one of back doors and pressing central lock , this way will lock all doors and the boot. Its a bit complicated , the key it unlocks all doors manually , but locks just the driver door . Can you tell me how to repair this problem and the key signal problem , the key signal it doesnt work, i checked the fuse box but cant find anything . Thank you very much

How long has your 1993 Mercedes-Benz 190E had this problem?

few months