Chevrolet Repair Questions? Ask a Mechanic for Answers ASAP
You can try to do a relearn on the pas key system. If it works, great. If it does not, then you will need to have the system scanned with a class 2 scanner to find out what component has failed. Normally the ignition lock cylinder goes bad or the wires to it break from all of the flexing when you turn the key. But because there are so many other possible reasons, it is best to have the system scanned before throwing parts at it. Follow the instructions below to the letter. Thanks
30 Minute Learn Procedure
Important: The vehicle learns the PasslockTM Sensor Data Code and/or password XXXXX the next ignition switch transition from OFF to CRANK. You must turn the ignition OFF before attempting to start the vehicle.