Conditions for Running the DTC

WARNING: This page is about a different car, the 2007 GMC Sierra, 2007 GMC Cab & Chassis Sierra, 2007 Chevrolet Silverado, and 2007 Chevrolet Cab & Chassis Silverado. However, it is still accessible from the selected car via links, so may be relevant.

DTC P0112, P0113, P0116, P0117, P0118 are not set.
The engine is running.
The IAT 1 is colder than 10°C (50°F), low region.
The IAT 1 is warmer than 10°C (50°F), high region.
The start-up engine coolant temperature is colder than 51°C (124°F).
DTC P0128 will only run once per ignition cycle until a Pass, Fail or Disable condition exists.