Conditions For Running 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.

No TFP manual valve position switch DTC P1810.
The engine speed is greater than 450 RPM.
The time since the last gear range change is greater than 6 seconds.
The time since the last 4WD low state change is greater than 6 seconds.
The transmission output speed rise does not exceed 600 RPM within 2 seconds.