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 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 BCM? | 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 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 |
4 | Select the BCM 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 | |
6 | Does the scan tool display DTC B1000, B1652, B1656, B1657 or B1658? | Go to Diagnostic Trouble Code (DTC) List in Body Control System | Go to Step 7 |
7 | Does the scan tool display DTC B0802 or B0803? | Go to Step 8 | |
8 | Does the scan tool display DTC B1982 or B1983? | Go to Diagnostic Trouble Code (DTC) List in Engine Electrical |
