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 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  | ||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
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 body control module?  | 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 modules: 
 
 Does the scan tool display any DTCs?  | Go to Step 4  | Go to Symptoms - Doors  | ||||||||||
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, B1372 or B1382?  | Go to Diagnostic Trouble Code (DTC) List in Body Control System  | Go to Step 6  | ||||||||||
6  | Does the scan tool display any DTCs which begin with a P?  | Go to Diagnostic Trouble Code (DTC) List in Engine Controls  | Go to Step 7  | ||||||||||
7  | Does the scan tool display one of the following DTCs? 
 
 
 
 
  | Go to Symptoms - Doors  |