I have an '09 CTS-V which I purchased about a year ago. I'm having problems with the fob/key recognition. These are the symptoms, which don't all occur at the same time:
approach car, open door and the interior lights fail to come on and the seat fails to adjust
Approach car, doors do not unlock, after some time, doors will open
approach car, open door....ignition fails to come on/turn, DIC shows message electronic key not detected....it did let me into car
turn off car, open door and the radio continues to play...close and reopen door and radio usually turns off and seat goes to exit position.
I took it to the dealer, their reader said both fobs were bad (?!), so they were replaced and reprogrammed and several updates downloaded. Since then it has repeated some of the glitches, but has so far let me in and started.
How many receivers/antennas interact with the fob and where are they located? Am I looking in the right area? Any other ideas/possibilities?