Chevrolet Repair Questions? Ask a Chevy Mechanic for Answers ASAP
You can try a relearn of the system keys.
This 30-minute learn procedure should be used when all vehicle keys are desired to be replaced or reprogrammed. This procedure will erase all previously learned vehicle keys from the TDM. Once the 30-minute learn procedure has been completed, any remaining vehicle keys may be programmed using the Adding Keys procedure to ensure their continued functionality.
Important: The TDM learns the key transponder information upon the ignition switch transition from OFF to ON. You must turn the ignition OFF before attempting to start the vehicle.
If this does not work then you may have a theft module that has failed, and these not easy to bypass as they incorporate 2 systems into 1 and are fully computerized.
Any attempt at bypass would require an aftermarket module installed, and with this being a 2009, there is a good chance it could be under warranty.