The number(s) below refer to the step number(s) 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.
This step determines if an ignition switch power mode condition exists. The specified procedure will determine which diagnostic path is to be followed.
This step determines if a body control module (BCM) DTC based diagnostic path or a symptom based diagnostic path are to be followed.
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.
This step displays stored system related DTCs to be diagnosed.
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 | |
Important:: The engine may start during the following step. Turn OFF the engine as soon as you have observed the Crank power mode.
Does the ignition switch parameter reading match the ignition switch position for all switch positions? | Go to Step 4 | Go to Power Mode Mismatch in Body Control System | |
Select the body control module display DTCs function on the scan tool. Does the scan tool display any DTCs? | Go to Step 5 | ||
Does the scan tool display any DTCs which begin with a "U" ? | Go to Diagnostic Trouble Code (DTC) List in Data Link Communications | Go to Step 6 | |
Does the scan tool display DTC B1000, B1397 or B1398? | Go to Diagnostic Trouble Code (DTC) List in Body Control System |