Symptoms - Vehicle Access. GMC Truck TopKick C-Series (Conventional) C4/C5 2008

For 1990-2009 cars only

Makes 🢒 GMC_Truck 🢒 2008 🢒 TopKick C-Series (Conventional) C4/C5 🢒 Body Systems 🢒 Vehicle Access 🢒 Symptoms - Vehicle Access

Important: The following steps must be completed before using the symptom tables.

Perform the Diagnostic System Check - Vehicle , before using the symptom tables in order to verify that all of the following are true:

•	There are no DTCs set.

•	The control modules can communicate via the serial data link.

Review the system operation in order to familiarize yourself with the system functions. Refer to Power Door Locks Description and Operation .

•	Inspect for aftermarket devices which could affect the operation of the rear window defogger. Refer to Checking Aftermarket Accessories .

•	Inspect the easily accessible or visible system components for obvious damage or conditions which could cause the symptom.

Faulty electrical connections or wiring may be the cause of intermittent conditions. Refer to Testing for Intermittent Conditions and Poor Connections .

Refer to Power Door Locks Inoperative in order to diagnose the symptom.