Key unlocks doors but won't start engine [W204]

[originlabs]

Hi All,

Just picked up a 2008 W204 which came with 2 keys. Both keys lock / unlock the doors, and the IR transmitters on both appear to work it I point them at my camera and press any of the buttons.

Only one of the keys will actually start the engine. When I put the bad key in the lock there is no 'whirring' sound.

Done a search for coding keys, but most of the information I've found is for pre-2007 cars.

Is this key faulty? Can this key be re-coded or do I need a new one directly from MB?

Cheers,

Matt

 

[andy27168]

Hi,
It sounds as if the key is faulty, it will need to be replaced though you could try and take it apart as there is a transducer coil that on some types of key that can fall off the PCB if the key was jarred sharply or dropped, then as long as the coil is not damaged you could try to resolder it on the board though this might be a bit hit or miss, as it is very small and surface mounted IIRC.
A new key from MB is approx. £227, might be a tiny bit less as you won,t need a new metal key as you should be able to salvage the one from your old key.
You will also need ID and prove of address and ownership of the car, before MB will even order a replacement key for you.

 

[jotter22]

How did you pick it up if it wont start your car?

Tony.

 

[renault12ts]

How did you pick it up if it wont start your car?

Tony.

Read post#1 again...carefully.

 

[originlabs]

Thanks for the replies guys. I'll have to wait for the V5 to come through and then order a replacement key. Hopefully the dealer I bought the car from (small independent, not a main) will cover the cost, as the car was sold with 2 working keys, one of which had a 'flat battery'.