GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Cadillac 🢒 2003 🢒 Escalade ESV 🢒 Body and Accessories 🢒 Navigation Systems 🢒 Diagnostic System Check - Navigation System

Test Description

The numbers below refer to the step numbers on the diagnostic table.

  1. 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.

    2.

  2. Checks for DTCs for each module of the system.

    3.

  3. 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.

Step

Action

Yes

No

Schematic Reference: Navigation System Schematics

1

Install a scan tool.

Does the scan tool power up?

Go to Step 2

Go to Scan Tool Does Not Power Up in Data Link Communications

2

  1. Turn ON the ignition, with the engine off.
  2. Attempt to establish communication with the navigation radio.

Does the scan tool communicate with the control modules?

Go to Step 3

Go to Scan Tool Does Not Communicate with Class 2 Device in Data Link Communications

3

Select the display DTCs function on the scan tool for the navigation radio.

Does the scan tool display any DTCs?

Go to Step 4

Go to Symptoms - Navigation Systems

4

Does the scan tool display any DTCs which begin with a "U"?

Go to Step 5

Go to Step 6

5

Does the scan tool display U2153?

Go to Diagnostic Trouble Code (DTC) List

Go to Scan Tool Does Not Communicate with Class 2 Device in Data Link Communications

6

Does the scan tool display DTC B1000, B1004, B1007, or B1009?

Go to Diagnostic Trouble Code (DTC) List in Body Control System

Go to Step 7

7

Does the scan tool display DTC B1327 or B1328?

Go to Diagnostic Trouble Code (DTC) List in Engine Electrical

Go to Diagnostic Trouble Code (DTC) List