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.
The symptom list in Symptoms will determine the correct diagnostic procedure to use.
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 Powertrain Control Module? | Go to Step 3 | Go to Scan Tool Does Not Communicate with Class 2 Device in Data Link Communications | |
Select the PCM display DTC function on the scan tool. Does the scan tool display any DTCs? | Go to Powertrain On Board Diagnostic (OBD) System Check in Engine Controls 3.4L |