Conditions for Running the DTC

WARNING: This page is about a different car, the 2002 Oldsmobile Bravada, 2002 GMC Envoy XL, 2002 GMC Envoy, and 2002 Chevrolet TrailBlazer. However, it is still accessible from the selected car via links, so may be relevant.

The engine is running.
The system voltage is greater than 8.5 volts.
The intake air temperature (IAT) is greater than -7°C (19°F).
DTCs P1481 and P1482 are not set.
The engine speed is less than 3200 RPM.
The engine speed is not changing more than 250 RPM for 5 seconds.
Fan command is greater than 0%.