Immobiliser

[lexusisfan]

Guys,

I have owned a few cars before the Lexus, but never came across this before.

The Lexus key come with a little black oval shape sensor (?), which according to the previous owner, needs to be attached to the key, otherwise the car won't start.

Well, a few days ago my car wouldn't start and the red immobiliser light would flash, which gives me an indication that the car wasn't recognising the immobiliser.

Does the black sensor need batteries or something done to it? (sorry if the question sounds silly)

The sensor which I'm referring to is this:

Thanks for your help!

[sparkystav]

Must be an aftermarket thing because that's not standard at all