Conditions for Setting the DTC
WARNING: This page is about a different car, the 2004 GMC Sierra, 2004 GMC Cab & Chassis Sierra, 2004 Chevrolet Silverado, and 2004 Chevrolet Cab & Chassis Silverado. However, it is still accessible from the selected car via links, so may be relevant.
The IAT Sensor parameter is less than -39°C (-38°F) for more than 10 seconds. This is equal to more than 4.86 volts on the IAT signal circuit as measured by the ECM.