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 symptoms 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.
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At this point you have determined all DTCs applicable to the horn system. Refer to Symptoms - Horns for further horn system diagnosis. Any other codes displayed from the listed modules do not apply to horns and should be diagnosed in the applicable section.
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 Communicate with Class 2 Device in Data Link Communications |
Does the scan tool communicate with the module? | Go to Step 3 | Go to Scan Tool Does Not Communicate with Class 2 Device in Data Link Communications | |
Select the RCDLR module display DTCs function on the scan tool. Does the scan tool display any DTCs? | Go to Step 4 | Go to Symptoms - Horns | |
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 Communications | Go to Step 5 | |
5 | Does the scan tool display DTC B1656? | Go to Diagnostic Trouble Code (DTC) List in Body Control System | Go to Step 6 |
Does the scan tool display DTC B1327 or B1328? | Go to Diagnostic Trouble Code (DTC) List in Engine Electrical | Go to Symptoms - Horns |
