Diagnostic Aids
WARNING: This page is about a different car, the 2010 Chevrolet Cobalt. However, it is still accessible from the selected car via links, so may be relevant.
Depending on the output from the turbocharger, an IAT sensor 2 signal circuit that is shorted to the intake air pressure signal circuit may cause the IAT Sensor 2 parameter response to be erratic or become stuck at a given value.