My key is no longer recognised by my 2017 Focus. The spare still works. Does anyone know how to reprogram the key?

4 minutes ago, AB100 said:

My key is no longer recognised

There are 2 seperate and unconnected functions to your keyfob. Is the problem that the remote lock/unlock won't work using the buttons OR is it the car won't start ?

Depends which it is, as to what needs programming.

The issue is the car won’t start and car says “no key detected” (nor do the doors lock/unlock by touching them). I can open the car pushing the remote button. Can also start the car by putting it in the area inside the central console.

my spare key works fine.

It will be the transponder chip in the keyfob which is not being read. Has the keyfob been dropped on a hard floor, or has the key been near any strong magentic field ?

Not that I’m aware of. Do you think I’ll need to get a new one from a Ford dealer then?

1 hour ago, AB100 said:

 Do you think I’ll need to get a new one from a Ford dealer then?

Not unless you want your wallet emptied!

You can reprogramme the key back into your car using the licenced version of ForScan (£10) assuming that the transponder chip has not been damaged in some way.

Download the software from here:- https://forscan.org/home.html

You will need the windows version (Free) and then buy the extended licence.

You will also need an ELM327 lead to connect your laptop to the OBDII port of your car

https://tunnelrat-electronics.fwscart.com/USB_Modified_with_switch_ELM327/p4541936_17045457.aspx

Once you have installed the software then you will be able to check the key and reprogramme the car.

Thanks, I don’t suppose you know of an Apple version rather than Windows?

Not I know of. Forscan is as close as you will get to the manufactures software, its used by most people on the forum. Also to do programming you have to use the wired version not Wifi/Bluetooth.