Diagnostic Starting Point - Data Communications

Begin the system diagnosis with Diagnostic System Check - Vehicle (with HP2) or Diagnostic System Check - Vehicle (without HP2) . 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.