Diagnostic Aid
If vehicle is not equipped with U42 ignore DTC U1000 if set in the radio. This applys to early build vehicles only.
Test Description
The numbers below refer to the step numbers on the diagnostic table.
-
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.
-
Checks for DTCs for each module of the system.
-
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 |
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 | |
Select the display DTCs function on the scan tool for the navigation radio. Does the scan tool display any DTCs? | Go to Step 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 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 | |
