Nostromo

Had the 2011 home for a day, went out with my old key fob (the one I didn't leave at the dealership for some work), and it doesn't work whatsoever. The light blinks, but it won't lock/unlock/start the car.

I assume I need it resynced to the car, but every google I've found is for older models than our B8. Any tips - besides going to the dealer tomorrow?

Moviela

Were they flashing the comfort and convenience module? They need both keys present to do that properly. You need to take it in and have it done.

My understanding is the VAGcom has to chat with the mother ship online to make it work.

audi8k

Also remember to bring the third (little plastic) key.

Nostromo

Brings up a question I've had: how does the key system work? Especially the plastic key.

I originally assumed the key fob communicates by radio with the car to start the ignition, but then there's that plastic emergency key...

audi8k

Yes it's radio. Also in the "plastic" key, there is an RFID chip. My understanding is that the chip is powered by the radio signal, so it doesn't need a battery. (It's a short range when inserted.)

Nostromo

RFID chip - of course!