Diagnostic Starting Point - Retained Accessory Power. GMC Truck Envoy

For 1990-2009 cars only

Makes 🢒 GMC_Truck 🢒 2003 🢒 Envoy - 4WD 🢒 Body and Accessories 🢒 Retained Accessory Power 🢒 Diagnostic Starting Point - Retained Accessory Power

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

•	Class 2 communication status

•	"U" codes which indicate module communication or circuit failure

•	"B" codes which indicate a possible body function or circuit failure

•	The status of any "U" or "B" codes