Does anyone know how to reprogram a ford focus 2009 key after changing the car battery

Hi,

There shouldn't be any need to reprogram the key after a battery change.

Has your key stopped working? Is it button start or key barrel ignition?

Key has stopped working, have to lock car manually and its barrel ignition

13 hours ago, RussellA said:

Key has stopped working, have to lock car manually and its barrel ignition

Have you tried changing the fob battery as well as the car battery? If the fob battery is definitely good then you can try a locking re-sync.

Turn ignition on (not engine). Then turn key back to off, then ignition, then off, then ignition, 4 times quickly. You should hear a beep, then press anyof the locking buttons on the fob. That should re-sync the fob if it's gone out of sync, but that doesn't usually happen after a battery change.

Thanks but ive already tried that and get the beep but doesn't sync after I press a button on the fob

Fob battery flat? New ones are not always good ones. Fob battery installed upside down? The battery will fit in the fob either way up. Check the Fob battery with a multi meter if you have one.

1 hour ago, RussellA said:

Thanks but ive already tried that and get the beep but doesn't sync after I press a button on the fob

In that case there is most likely a fault with the fob rather than the car. Either the battery is flat or not installed correctly, as suggested above.

The only other potential fault would be the remote key module in the roof lining, but it would be very unusual for that randomly break during a battery change. Unless the car was left standing for a while to cause a flat battery?