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Symptoms - Cellular Communication: Notes

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Important:  The following steps must be completed before using the symptom tables.

  1. Perform the DIAGNOSTIC SYSTEM CHECK - CELLULAR COMMUNICATION  before using the Symptom Tables in order to verify that all of the following are true:
    • There are no DTCs set.
    • The control module can communicate via the serial data link.
  2. Review the system operation in order to familiarize yourself with the system functions. Refer to ONSTAR DESCRIPTION AND OPERATION  .