Test Description
The number(s) below refer to the step number(s) on the diagnostic table.
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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.
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The symptom list in Symptoms will determine the correct diagnostic procedure to use.
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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 | Did you perform the Battery Inspection/Test? | Go to Step 2 | Go to Battery Inspection/Test | ||||
2 |
Does the scan tool power up? | Go to Step 3 | Go to Scan Tool Does Not Power Up in Data Link Communications | ||||
Attempt to establish communication with the following components:
Does the scan tool communicate with the PCM and VTD? | Go to Step 4 | Go to Scan Tool Does Not Communicate with Class 2 Device in Data Link Communications | |||||
Select the PCM and VTD display DTC 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 Scan Tool Does Not Communicate with Class 2 Device in Data Link Connector Diagnosis | Go to Step 6 | |||||
6 | Does the scan tool display any DTCs in the PCM which begin with a P? | Go to Diagnostic Trouble Code (DTC) List/Type in Engine Controls 4.3L , Diagnostic Trouble Code (DTC) List/Type in Engine Controls 5.0/5.7L , Diagnostic Trouble Code (DTC) List/Type in Engine Controls 6.5L or Diagnostic Trouble Code (DTC) List/Type in Engine Controls 7.4L | Go to Step 7 | ||||
7 | Does the scan tool display any DTCs in the VTD which begin with B? | Diagnostic Trouble Code (DTC) List/Type in Theft Deterrent | System OK |
