Diagnostic Aids
WARNING: This page is about a different car, the 2018 Chevrolet Suburban 3500 HD. However, it is still accessible from the selected car via links, so may be relevant.
The parameters for intake air temperature and engine coolant temperature should be within 3°C (5°F) of each other if the ignition has been Off for greater than 8 h.
High resistance in the circuits of the component may set DTC P0128 without setting the DTC for the component: