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.

A low voltage DTC in multiple modules indicates a concern in the charging system.
Inspect the ECM gound connection G106 (4.3L LU3) or G103 (all other engines) to ensure that they are clean and tight.