Keyfob mystery

[Prof]

I have a square-ish thingy on my car keys - seems about 1" x 1" and about 1/8" inch think  (25mm x 25mm x 6 mm for you metric heads).  Inside is just a pcb with a copper loop on it - some kind of RF passive arial.

Car is fitted with a TOAD alarm.

When I try and start the car without this thing on the keys, it doesn\'t - so it\'s part of the immobilizer circuit.

My question is this - is this part of the original car immobilizer or is this a TOAD add on ?

Also, does anyone know how this gizmo works - is there a receiver/transmitter box somewhere nearby that I have missed ?

Cheers for any answers ! :2Confused

[nikp]

Not sure if the FD came with an original immobilsor.

What TOAD alarm have you got? I have a TOAD Ai606 which doesn\'t require this. However, i did have an Cat 2 immobilisor fitted to my previous calibra, which had one of these sorts of things - there was a receiving loop in the steering column cowl.

[Prof]

Not sure if the FD came with an original immobilsor.

What TOAD alarm have you got? I have a TOAD Ai606 which doesn\'t require this. However, i did have an Cat 2 immobilisor fitted to my previous calibra, which had one of these sorts of things - there was a receiving loop in the steering column cowl.

Not sure what TOAD it is - the keyfob for the toad has 4 buttons - and I have the 2 stage movement sensor and another receiver unit attached as well.  It does the doors, and immobilizes the car.

It came with it when I got the car, and there was no paperwork for the alarm.  Car is an FC vert.

I plan to put one of those 2-way remote alarms in, which does everything the toad does, as well as Turbo timer and some other goodies - such as remote start.  Thing is I need to understand how the extra keyfob works so I can defeat it intelligently !