Key RFID

[Meir]

Originally Posted by clueless1

Yes, that info may help. If it’s just a passive antenna does that = there’s no reason I can’t just directly power it via relay? (that’s the core of the issue ... I’m not trying to “hack the immobilizer”; instead I am trying to enable/power the factory transponder antenna ON to look for a pill on remote start).

Is the passive antenna powered with constant 12V positive? And would it matter which side (which of the two wires) was powered (via relay)?

as mentioned the antenna itself is passive, but it is connected to the immobilizer module. the immobilizer module is powered by the orange wire coming from the ignition switch.
here is a diagram of the immobilizer module.

[thom4782]

Easiest solution - buy a second key and have a dealer or indie program it for your car.

[Qmulus]

I am not sure I should get involved in this, but I think I might know how a remote start could work. Basically, you would need another programmed transponder. That would be put in another reader coil in the remote start that would be relayed to the coil reading module instead of the original coil when the remote start was activated via its transmitter. So, unless the remote start transmitter was used, it would function normally. If the remote start was used, you would still need the mechanical key to unlock the column and drive the car. I would assume there are interlocks for the parking brake and some sort of neutral safety mechanism.

So, the only real danger of cars being stolen would be by having that extra transponder in the car that is used by the remote start. You would need to know it has the remote start and where it is, then remove the transponder and put it in a key that would work in the lock so you could use it as a normal key. If the remote start's transponder was glued in, it would be extremely difficult to do this, to the point I would say the risk would be negligible.

As for the remote start, it would need to energize the 86s terminal when switched over to the remote start transponder. That would make the coil reader module read the transponder and start the transponder authentication process. Once that is done, you energize the ignition and then starter.

All that said, I have never installed one of the devices that is mentioned, so I have no idea how the configuration needs to be set up to get it to work or if the device in question can do this, but I would bet it can. I personally wouldn't put one in my Boxster, but YMMV.