Important: The following steps must be completed before
using the symptom tables.
- Perform the
Diagnostic System Check - Vehicle
in Vehicle DTC Information. Before using the Symptom Tables, verify
that all of the following are true:
• | The control module can communicate via the serial data link. |
- Review the system operation in order to familiarize yourself with the
system functions. Refer to
OnStar Description and Operation
.
- Perform the
OnStar Symptom Diagnosis
.
This symptom table will enable the user to verify the customer complaint and narrow
it to its source.
Visual/Physical Inspection
• | Inspect the easily accessible or visible system components for obvious
damage or conditions which could cause the symptom. |
Intermittent
Faulty electrical connections or wiring may be the cause of intermittent conditions.
Refer to
Testing for Intermittent Conditions and Poor Connections
in Wiring Systems.
Symptom List
Refer to a symptom diagnostic procedure from the following list in order to
diagnose the symptom: