B0785 06
WARNING: This page is about a different car, the 2010 GMC Sierra and 2010 Chevrolet Silverado. However, it is still accessible from the selected car via links, so may be relevant.
The TCCM detects 1.6 V or less for 1.5 seconds on the 2WD HI indicator control circuit when the 2WD HI indicator is commanded OFF.