Circuit/System Verification
WARNING: This page is about a different car, the 2009 GMC Sierra, 2009 GMC Cab & Chassis Sierra, 2009 Chevrolet Silverado, and 2009 Chevrolet Cab & Chassis Silverado. However, it is still accessible from the selected car via links, so may be relevant.
Perform the scan tool Stolen Vehicle Slow-Down Clear. Verify DTC P162B is not set. If the DTC is set, replace the vehicle communication interface module and retest. If the DTC sets again, replace the ECM.