For those C6 and reportedly C7 owners the FOB system seems to be prone to failure regardless of condition of batteries in the FOBs. My 2011 Grand Sport with 6000 miles, garage kept& covered, several months ago no longer recognized either key FOB. Performing the emergency unlock procedure got the car started and to my Chevy dealer. Their first attempt to fix was failure and their test gear said FOB batteries ok. After returning home car would not unlock again. After researching issue on Corvette Forum appears issue common to C6 and C7 Corvettes.
Main solution seems to be to replace the receiver in the car (in the dash) with new unit as it deteriorates over time apparently. In the benign conditions of my ownership this should have taken 50 years IMO. Second visit to dealer with their "Corvette Specialist" fixed issue but took their working on and off the better part of 2 Weeks (they were nice enough to keep it in the shop) and using their Tech 2 support to work with Michigan and having reportedly to replace a mislabeled receiver. Cost was a staggering $1000.00 (if they had charged me for all labor would have been much more I suspect).
My reason for posting this is given the painful story of these relatively simple electronics not being able to be quickly diagnosed and repaired (let alone the failure in the first place) makes me wonder how GM thinks they will be able to successfully develop self driving cars in a few years when they cannot even diagnose a FOB system....????
For C6 and C7 owners get ready to get really upset if you have not already!