Ford to thwart the 'grabbers': Car key beams signal to ignition from short range. Susan Watts reports

AN ELECTRONIC implant first used to tag pigs is the basis of an anti-theft device for Ford cars unveiled yesterday.

The 'Safeguard' system, to be incorporated in all Ford Escorts from now and all Ford vehicles by the end of the year, is aimed at thwarting opportunist car thieves.

It should also make life difficult for technologically literate criminals, such as those who developed the 'grabber', a device which convinced manufacturers they had to stay an electronic step ahead.

Grabbers let thieves record the radio or infra-red signal as car owners lock their remote central locking system. They simply play the signal back once the owner is out of sight to unlock the car.

Ford insists its new system is not vulnerable to such devices, since the low-frequency radio signal it uses has a range of just 2 to 3cm. This is far enough to link a tiny transmitter-receiver, or transponder, encased inside the Ford key, and an antenna looped round the ignition.

The key's transponder holds a unique code - one of 18 trillion possibilities - matching a code stored in the memory of a control unit inside the steering column.

When the key is slotted in, the control unit sends a 'power' signal to the transponder, which sends out its code. If the match is verified, the car starts. If not, its engine management system and fuel pump remain immobilised. The same is true if there is no key in the ignition, making it impossible, Ford claims, to 'hot wire' the car.

The new owner is supplied with a red master key, from which they can programme spares. The master must then be kept in a secure place.

If a key is lost or stolen, a Ford dealer re-programmes the car's central control unit, and a new master.

If someone did manage to pick up the code by recording the radio signal it would be of little value unless they could programme the code into a 'blank' transponder. This would be difficult to accomplish, according to the Texas Instruments engineers who developed the electronics.