Diagnostic Instructions

WARNING: This page is about a different car, the 2019 GMC Savana 3500, 2019 GMC Savana 2500, 2019 Chevrolet Express 3500, and 2019 Chevrolet Express 2500. However, it is still accessible from the selected car via links, so may be relevant.

Perform the Diagnostic System Check prior to using this diagnostic procedure: Diagnostic System Check - Vehicle
Review the description of Strategy Based Diagnosis:Strategy Based Diagnosis
An overview of each diagnostic category can be found here: Diagnostic Procedure Instructions