Symptoms - Data Communications
Symptoms - Data Communications |
Important | ||
The following steps must be completed before using the symptom tables. |
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1. |
Perform the
Diagnostic System Check - Vehicle
before using the symptom tables in order to verify that all of the following are true:
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• |
There are no DTCs set.
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• |
The control modules can communicate via the serial data links.
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2. |
Review the system operation in order to familiarize yourself with the system functions. Refer to
Data Link Communications Description and Operation
.
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Visual/Physical Inspection |
• |
Inspect for aftermarket devices which could affect the operation of the systems. Refer to
Checking Aftermarket Accessories
.
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• |
Inspect the easily accessible or visible system components for obvious damage or conditions which could cause the symptom.
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Intermittent |
Faulty electrical connections or wiring may be the cause of intermittent conditions. Refer to Testing for Intermittent Conditions and Poor Connections .
Symptom List |
Refer to a symptom diagnostic procedure from the following list in order to diagnose the symptom:
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Scan Tool Does Not Power Up
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Scan Tool Does Not Communicate with High Speed GMLAN Device
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Scan Tool Does Not Communicate with Mid Speed GMLAN Device
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Scan Tool Does Not Communicate with Low Speed GMLAN Device
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Scan Tool Does Not Communicate with Chassis High Speed GMLAN Device
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