Anytime man!! These types of questions really break up the nightly questions. Although this one is having me really think and do some research. I like it!
1. Does the Hyundai constantly broadcast a wakeup signal to wake the smart key fob
Yes, There is constantly a coded signal being sent out looking for the key in the pocket
2 if so, what frequency does the hyundai put out,
FM and is 433.92 Mhz (I think thats what you are looking for?)
Can you say more about what the coded message looks like.
Sorry, for that, I have no idea. its a very crypted code to prevent theft, I do know that.
3 If the key is the first to initiate the dialog:
Like stated above, its at 433.92MHz
how is it coded – what does it say?
Once again, that I am honestly not sure of. I made a phone call to a contact I have a manufacture who is responsible for the smart key operations on that brands car and he would not mention any of the code/encryption to me.
4. Is the key a bi-directional transponder?
They offer both. Unidirectional and Bi-directional. Just depends on the model and package.
What frequencies does it receive?
FM and 125KHz
What frequency does it respond over while outside the car
FM and I am not sure about the last part of this question.
5 does the smart fob use different frequencies once inside the car?
Yes, it uses RF inside the car to send signals and different verification codes to different control modules to start the car (smart key computer, Engine control computer etc)
What frequency (or plural) and data structure does it receive inside the cabin
Not sure on the Data structure? Not sure on the frequency, I ll have to double check that tomorrow.
What frequencies and data structure toes it reply with inside the cabin.
Ill check on this tomorrow as well.
6 How does the car know the owner has exited the cabin, so he can lock doors.
through the in car antenna's located in various places (Upper B pillers, head liner, etc.)
When the smart fob exits the cabin are the same send and receive frequencies used by fob?
Does the tell the car it is outside, or does the car probe for a fob outside.
It no longer receives the RF signal and frequency "ping back" from the key on the inside antennas. which is why you cant lock a smart key in the car.
If two authorized keys are in the car, can either lock the car, or must it be the driver who just shut off the vehicle.
This is very confusing for the car, even more so if you have memory seats assigned to keys, radio stations and climate control settings. both can lock/unlock the doors.
Sorry thats all the Info I really have. but please feel free to explain anything I had questions on, or did not answer clearly. I will do my best to get the most accurate answer for you. Sorry it took me a while to get back to you!