Camshaft Position Sensor Circuit Range/Performance

Well it means the computer more than likely lost an input signal from the cam sensor for at liast a few revolutions. The specifics can get real wordy.

HAve you cleared the code to see if it comes back.
Cam sensor codes usually do come back.
Most GM cars will run just fine and forever with a bad cam sensor code.
The sensor is cheap and fairly easy to replace.
Replacing it "usually" fixes it.
Many have a magnet on the cam gear that can come loose and move and still lose the signal even though the sensor itself is good.