Ford has enhanced the keyless entry technology on new Fiesta and Focus models to make them harder to steal.

The keyless entry fobs now become disabled when not in use to prevent “relay attacks”, where thieves use a computer device to boost the signal from keys stored inside a property to steal a car.

A new motion sensor inside the Ford keyfob detects when it has been stationary for longer than 40 seconds and triggers a sleep mode, which will not respond to attempts to hack its signal.

Moving the keyless fob by picking it up inside the home and taking it to the car will restore full functionality. The Ford fobs are designed to operate only within a two-metre radius of the cars they are bonded to.

The Fiesta and Fiesta Van are already being delivered with the new fobs, followed by Focus production from next month.

Simon Hurr, Ford’s security specialist, said: “The online availability of devices which have no place in public hands has long been a problem for Ford, our industry and crime fighters. We are pleased to respond with a simple but effective solution – swiftly implemented to help protect owners of our top-selling cars.” 

Owners of existing Fiesta and Focus models can have their security upgraded with replacement fobs, priced from £65 (Fiesta), £72 (Focus) plus 0.9 hours labour to programme and test.

Ford will be rolling out the same motion-sensor technology across its other models in the next two years.

Another innovation on new Ford models is a 10-minute software lockdown if the vehicle’s alarm is triggered. This reduces the possibility of rapid illegitimate programming of keys for the car via the OBD.

Keyless entry systems are  blamed, in part, for an increase in car thefts in England and Wales. Data suggests that thefts have increased by 15% since 2016/17, and 40% over the past five years.