2005 C4 key replacement

[tomaskriv]

Thanks for explaining me this. So in our case mobile locksmith replaced transponder. Well added new one because now the original key starts the car only with added transponder. But then WHY it is not locking/unlocking the doors if same key was able to d othis even when the transponder was damaged and key was unable to start the car. After the locksmith added transponder end reprogrammed the key, locking function was lost and he was scratching his head without any logical explantaion...

[tomaskriv]

https://www.ebay.ie/itm/433MHz-3-Button ... 3345130966

https://www.aliexpress.com/item/4000061 ... 4c4daS45Ls

these eare the keys we purchased

[GiveMeABreak]

As I mentioned - it really does depend on the type of system you have - they can differ slightly - so as you can see on some the electronics send out different codes depending on the function - and as long as the fob is authorised (programmed) the remote functions should work.

The coded message sent to the receiver (in the car) by each remote control is composed of the following codes:

• A fixed code linked to the key
• A rolling code matched with the vehicle’s receiver
• A code corresponding to the action to be performed
• A code corresponding to the condition of charge of the batteries

[Paul-R]

As long as the new key will start the car then I would try resynching again.

[tomaskriv]

This is all we can do for now.

[tomaskriv]

Hi Marc
Can you tell donwe need ASK or FSK key?

Thank you.

[Paul-R]

If it's the same as the one I bought for our 2013 X7 it'll be ASK.