Diagnostic System Check - Navigation System

A Diagnostic System Check - Navigation System:

TEST DESCRIPTION
The number(s) below refer to the step number(s) on the diagnostic table.
2. Lack of communication maybe due to a partial or a total malfunction of the class 2 serial data circuit. The specified procedure will determine the particular condition.
3. The symptom list in Symptoms will determine the correct diagnostic procedure to use.
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.