Alright folks.

I tried to use my spare key recently, and it just doesn't work to lock/unlock the car. If I unlock the car with my first key, then I can use the spare one to start the engine, etc, but it doesn't lock/unlock the doors, i.e. none of the buttons of the fob seem to be working.

I thought it was the battery, but I replaced that today, and still nothing. I tried to reprogram it (turn the ignition through 4 cycles until you hear a beep, then press the unlock button on the fob), but it doesn't respond to that either.

Any ideas? Is it just fried?

If it is fried, where can I get a replacement and how do I program it without having to pay wheeler dealer prices?

It's easy enough to do, just buy a second hand one from a well known auction site.

Once you have it, you'll need to change the transponder chip from your old remote into the replacement, add your horseshoe to the replacement then programme the replacement fob as you would normally do.

I.E. Ignition on and off 4 times in six seconds, then press a button.

Have you checked that the battery contacts are clean and making good contact?

Sometimes the buttons can pack though but if the transponder still allows the car to start and the blade still manually opens the doors/turns the ignition then all you would need at most is a new RCL circuit.

Buy a second hand fob off eBay with all the bits intact and then just swap over the button side of the fob so that you will have the original chip nd blade but just new circuit then re-programme as you've tried before.

http://www.ebay.co.uk/itm/FORD-S-MAX-C-MAX-ST-NEW-FOCUS-MONDEO-FIESTA-REMOTE-KEY-FOB-/290919093055?pt=UK_CarsParts_Vehicles_CarParts_SM&hash=item43bc21133f