W211 Key fob wont Lock

[W210/1]

I have 3 button key fob One for opening - One for closing - One for the boot.

Pressing the button to lock the car will not lock but however when I manually lock the car the fob will open and it also works for the boot.

Any ideas ?

 

[Dec]

It could be the button inside the fob or it could be the plastic part of the case that is worn out.

Try testing the fob while viewing the end of the fob through a digital camera… press particularly hard on the Lock button, if it lights up like the other 2 buttons… while pressing the Lock button very hard… then its likely to be the part of the fob case that covers the button that’s at fault rather than the button beneath it.

[YOUTUBE HD]zQhwvjw29NA[/YOUTUBE HD]


Is your fob the same as the one below?
Source… REF 3SW7 Micro Switch 3X Mercedes Benz W202 W210 W220 W211 KEY FOB Remote Button | eBay

Edit; the video below will be easier to understand, a better illustration of the camera test in the last 8 seconds of the video.

[YOUTUBE HD]GoRP1oi0sYk[/YOUTUBE HD]


Dec

 

[W210/1]

Thanks Dec - Your post was spot on - Mine was the 3 button Fob - The button on the PCB for locking had come away from the PCB - I re soldered and alls well