Fiesta and Focus are the first Fords to get the tech.
Keyless car crime is an ongoing problem with new cars in Europe, and it's on the rise.
Thieves can buy a device over the Internet that allows them to intercept the signal between the key fob and car and generate an entry code that enables them to get inside the car and drive off – that is, if the security systems on the car aren't up to date with the latest technology to prevent exactly this kind of attack.
The key fobs for the car are fitted with a motion sensor which detects whether or not they have moved for 40 seconds – if they haven't, the key fobs are put into a "'sleep mode," meaning the fob won't interact with the sort of equipment criminals use to gain access to keyless-equipped cars when the keys are nearby.
"The online availability of devices which have no place in public hands has long been a problem for Ford, our industry and crime fighters," said Ford security specialist Simon Hurr. "We are pleased to respond with a simple but effective solution – swiftly implemented to help protect owners of our top-selling cars."
You don't even need to go out and buy a brand new Fiesta or Focus to benefit from this new technology either. If you already own the latest generation of either model, you can get replacement secure fobs for just £65 / $85 (for the Fiesta), £72 /$94 (for the Focus), plus labor costs.
"This is great news for car owners and the wider automotive industry," said Richard Billyeald, chief technical officer at Thatcham Research. "There is a known weakness in keyless entry systems, and we are pleased that Ford has come up with a simple and effective response on these big-selling models. We hope that other car makers will respond in a similar fashion."