Replacing the battery in the key fob

[Amsy]

Hi i recently bought a used CLk 240 key fob stopped working so I replaced the battery still not working I then bought a new fob case from Amazon for 9quid and swapped all the internal parts still not working any ideas ?

 

[Blobcat]

Does it start and stop the car?
Is it just the remote locking and unlocking that isn't working?

If it is just the remote unlocking there is a coil on the circuit board that comes adrift - you can if you're handy with a soldering iron solder it back on or replace it if it's completely snapped.

 

[LostKiwi]

Did you buy a used key fob to use with a different car to the one it was originally programmed for?

 

[Amsy]

Does it start and stop the car?
Is it just the remote locking and unlocking that isn't working?

If it is just the remote unlocking there is a coil on the circuit board that comes adrift - you can if you're handy with a soldering iron solder it back on or replace it if it's completely snapped.

No it won't start or lock the car mechanic checked all the fuses and they were fine he said after replacing the battery I will need to reset it but I don't have a manual for the car

 

[Amsy]

Did you buy a used key fob to use with a different car to the one it was originally programmed for?

No it was just the fob case that was replaced

 

[Blobcat]

You don’t need a battery in the key to start the car. There’s an inductive loop in the steering binnacle that reads the chip in the key.
Has the key ever worked ?