A140 Central Lock "problem"
 

Hi all,

I have a problem with locking my car with car key. The key locks only driver's or passanger's door but not all, like the central locking function is off.
The interior central lock button is working fine. I can lock/unlock all doors. Also, when I open driver's door all doors unlocks. But when I turn key to lock car only driver's door locks.

The car model is A140 from 1998.

It's driving me mad, please help.

RE: A140 Central Lock "problem"
 

Hi,

I´ve the same problem. I have a A190 2001. Someone can help us!

RE: A140 Central Lock "problem"
 

A tale of two keys - check the operation of your respective cars' locks with both remotes. If there is a difference, this may just be down to afault with one key or the car not recognising it properly. We had a similar problem with just one key, only unlocking driver's door, but if pressed twice would unlock all doors.

Our garage (non Merc but with fully Merc trained technicians) suggested it oculd be down to programing of keys. Anyway, we changed both keys batteries as a precautionbut there was no difference. One key worked fine, the other had to be pressed twice to get all doors to unlock (locking was normal).

Anyway, after changing a faulty dipped beam headlight bulb the problem disappeared. It is possible, with the A-Class electrical systme being so sensitive that something unrelated in the car could be loose or faulty and this could be evidenced in the locking system. Worth a try anyway !!

I beleive that it is a design fault.

Mercedes never expected anyone to actually lock it with the key manually as they all came with a central locking button. And that users would only potenially unlock the car with the key.

They only way to lock the car with the key is to press the buttons down on the back doors and passenger, then lock the remaining door with the key.

ALSO dont forget to lock the boot!