Test Description
The numbers below refer to the step numbers 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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This step tests for valid system power moding in all ignition switch positions.
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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 body control module? | Go to Step 3 | Go to Scan Tool Does Not Communicate with Class 2 Device in Data Link Communications | |
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Important: Open the driver door and leave it open during this test. This will disable the RAP power mode and eliminate this power mode from the power mode parameter list. 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 Class 2 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 body control module display DTCs function on the scan tool. Does the scan tool display any DTCs? | Go to Step 5 | Go to Symptoms - Roof |
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? | Go to Diagnostic Trouble Code (DTC) List in Body Control System | Go to Symptoms - Roof |
