Conditions For Running DTC

WARNING: This page does not describe the selected car, but rather 11 other vehicles, including the 2002 GMC Yukon XL, 2002 GMC Yukon, 2002 GMC Sierra, 2002 GMC Cab & Chassis Sierra, and 2002 Chevrolet Tahoe. 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.