Diagnostic Aids
WARNING: This page is about a different car, the 2006 GMC Yukon XL, 2006 GMC Yukon, 2006 Chevrolet Tahoe, 2006 Chevrolet Suburban, and 2006 Chevrolet Avalanche. However, it is still accessible from the selected car via links, so may be relevant.
A mechanical condition inside the front axle could prevent the shift fork from moving causing the motor to be stuck in one position. Refer to Symptoms - Front Drive Axle .