Test Description
The numbers below refer to the step numbers on the diagnostic table.
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This step verifies that the RAP power mode function is malfunctioning by checking functions internally enabled by the BCM.
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The BCM sends class 2 messages to other control modules via the serial data link, allowing them to operate in RAP power mode. 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 is checking for DTCs in the BCM.
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The presence of DTCs which begin with "U" indicate that other module is not communicating. The specified procedure will compile all the available information before tests are performed.
Step | Action | Yes | No | ||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|
Schematic Reference: Retained Accessory Power (RAP) Schematics | |||||||||||
Are all of the functions inoperative? | Go to Step 2 | Go to Control Module References in Body Control Systems for the applicable Diagnostic Systems Check for the system that does not operate | |||||||||
2 | Install a scan tool. Does the scan tool power up? | Go to Step 3 | Go to Scan Tool Does Not Power Up in Data Link Communications | ||||||||
Does the scan tool communicate with the BCM? | Go to Step 4 | Go to Scan Tool Does Not Communicate with Class 2 Device in Data Link Communications | |||||||||
Select the body control module 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 | Compare the DTCs listed below to the scan tool:
Are any of the DTCs shown on the scan tool? | Go to the appropriate DTC diagnostic table | Go to Control Module References in Body Control Systems for the applicable sub-section/DTC procedure | ||||||||
