Conditions for Setting the DTC

WARNING: This page is about a different car, the 2008 GMC Sierra, 2008 GMC Cab & Chassis Sierra, 2008 Chevrolet Silverado, and 2008 Chevrolet Cab & Chassis Silverado. However, it is still accessible from the selected car via links, so may be relevant.

The transfer case control module sees a incremental 8-volt reference signal that is not between 1.5-8.2 volts indicating a short to ground or open if low and a short to voltage if high.
The module does not receive a incremental impulse signal voltage between 0.5-4.6 volts.
The incremental low reference circuit has an open or high resistance.