Circuit/System Verification
WARNING: This page is about a different car, the 2008 Chevrolet Malibu. However, it is still accessible from the selected car via links, so may be relevant.
Engine running, observe the scan tool Steering Position Sensor Signal 1 and the Steering Position Sensor Signal 2 parameters while turning the steering wheel one full revolution. Each reading should be between 2.5-2.8 volts.