Yukon XL 2500 2WD V8-8.1L VIN G (2004)
Navigation System: Initial Inspection and Diagnostic Overview
Diagnostic Starting Point - Navigation System
DIAGNOSTIC STARTING POINT
Begin the system diagnosis with the Diagnostic System Check - Navigation System. The Diagnostic System Check will provide the following
information:
-
The identification of the control module(s) which command the system
-
The ability of the control module(s) to communicate through the serial data circuit
-
The identification of any stored diagnostic trouble codes (DTCs) and their status
The use of the Diagnostic System Check will identify the correct procedure for diagnosing the system and where the procedure is located.
Diagnostic System Check - Navigation System
DIAGNOSTIC SYSTEM CHECK
TEST DESCRIPTION
Steps 1-7
The numbers below refer to the step numbers on the diagnostic table.
2. Lack of communication may be due to a partial malfunction of the class 2 serial data circuit or due to a total malfunction of the class 2 serial data
circuit. The specified procedure will determine the particular condition.
3. Checks for DTCs for each module of the system.
4. The presence of DTCs which begin with "U" indicate some other module is not communicating. The specified procedure will compile all the
available information before tests are performed.