Diagnostic Aids

WARNING: This page is about a different car, the 2010 GMC Sierra, 2010 GMC Cab & Chassis Sierra, 2010 Chevrolet Silverado, and 2010 Chevrolet Cab & Chassis Silverado. However, it is still accessible from the selected car via links, so may be relevant.

The transfer case drain plug provides a good ground point.
The EL-49742 harness provides a good source for 12 V and ground.
Inspect the rear internal gear teeth for damage.
Visually inspect the VSS for cracks or damage.
Ensure the VSS is properly torqued to the transfer case housing.
This diagnostic relates to the VSS located in the transfer case and not the OSS located within the transmission.