The numbers below refer to the step numbers on the diagnostic table.
Lack of communication may be due to a partial or 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 on the class 2 serial data circuit. The specified procedure will compile all the available information before tests are perform.
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 modules listed above? | Go to Step 3 | Go to Scan Tool Does Not Communicate with Class 2 Device in Data Link Communications | |||||
3 |
Important: The engine may start during the following step. Turn the engine OFF as soon as you have observed the Crank power node.
Does the System Power Mode parameter reading match the ignition switch position for all switch positions? | Go to Step 4 | Go to Power Mode Mismatch in Body Control System | ||||
4 | Select the DTCs function on the scan tool for the following modules:
Does the scan tool display any DTCs for the modules listed above? | Go to Step 5 | |||||
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 6 | |||||
6 | Does the scan tool display DTC P0562, P0563, P0621, or P0622? | Go to Diagnostic Trouble Code (DTC) List in Engine Electrical |