Diagnostic Starting Point - Data Communications

WARNING: This page does not describe the selected car, but rather 6 other vehicles, including the 2009 GMC Savana Special, 2009 GMC Savana Camper Special, 2009 GMC Savana, 2009 Chevrolet RV Cutaway, and 2009 Chevrolet Cutaway. However, it is still accessible from the selected car via links, so may be relevant.

Begin the system diagnosis with Diagnostic System Check - Vehicle . The Diagnostic System Check - Vehicle will provide the following information:

The identification of the control modules which are not communicating
The identification of any stored diagnostic trouble codes (DTCs) and their status

The use of the Diagnostic System Check - Vehicle will identify the correct procedures to begin vehicle diagnosis. These must be performed before system DTC or symptom diagnosis.