3 Button Key Fob

[twiggi]

I have two 3 button key Fobs for my E270 (W211). One of them gave up the ghost last week - (wouldnt even turn in the ignition). Changed the batteries and it now starts the car but doesnt lock/unlock the doors. The little red light next to the close button doesnt light whilst on the good key fob it does. I eliminated the battery holder by swapping them over.

So - what do I do

(1) buy one off ebay and then try and swap the circuit board - anyone done this?
(2) go to the dealer and resynch - what is the resync process?
(3) go to the dealer and buy a new one.

Any feedback much appreciated

 

[type49]

If you buy one off ebay it will NEVER work. Dispite people's claims, you cannot re code a key to work in a different car - even Mercs themselves cannot do this. If it's a new key you're after, it has to come from Germany. You will need the logbook + proof of identity before your dealer will order a key & it may take 5 days to arrive.

 

[Big Gav]

Ive had the same prob over the weekend the forum lot have been a fantastic source of info.

How ever ive just got back from MB and it cost me £150.00 and as type49 says it will take 7 working days to come in then they have to sync the key with the car.

I too am very intriged on the syncing of the keys.
i tried all the methods noted on the site but none of them worked for me?
but as like twigi i lost my reb light fashy bit but still had the key engage the ingition? strange.