does it have a purpose? its just irking me, b/c people ask about it, and i dunno what to say...

 

You need that little blue mark to talk to the computer in the car. ..something like that.

 

yeah, I think it has to do with the chip inside....may be connected to it somehow.

 

yeah, the chip which allows the car to start is located underneath the blue cover.

 

yes. chip. w/o the chip your car won't start. you lose it, it's $70 (dealer quote) to get a new one b/c they need to reprogram one for you. it's a nissan security thing. a lot of cars have it nowadays--from Toyotas->VWs->Mercedes, etc.

 

Ya.. it looks like a passive key fob to me.. You put it in your ignition, your car generates some RF, it hits a type of "coil" behind the blue thingy, and that coil in turn generates some RF on another frequency. If it get's the reply correct, your car is allowed to continue on it's way.. if not, the fuel remains cut... Sound right??

-Tom Z.

PS.. Be careful with your fob around strong EM fields... I've heard that running it over one of those black security pads at a checkout could potentially warp it, and you wouldn't be able to start your car...