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.
The presence of DTCs which begin with a "U" indicate some other module is not communicating on the class 2 serial data circuit. The specified procedure will compile all the available information before tests are performed.
Step  | Action  | Yes  | No  | ||||||
|---|---|---|---|---|---|---|---|---|---|
Schematic Reference: Audible Warnings 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 listed above?  | 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 following control modules: 
 
 
 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 Scan Tool Does Not Communicate with Class 2 Device in Data Link Communications  | Go to Step 5  | |||||||
5  | Does the scan tool display DTC B1000, B1001, B1369, B1374, or B1379?  | Go to Diagnostic Trouble Code (DTC) List in Body Control System  | |||||||