Diagnostic Instructions (Communication Interface Module)

WARNING: This page is about a different car, the 2009 Saturn Outlook, 2009 GMC Acadia, 2009 Chevrolet Traverse, and 2009 Buick Enclave. However, it is still accessible from the selected car via links, so may be relevant.

Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure.
Review Strategy Based Diagnosis for an overview of the diagnostic approach.
Diagnostic Procedure Instructions provides an overview of each diagnostic category.