- Symptoms - Cellular Communication

Symptoms - Cellular Communication

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



1. Perform the Diagnostic System Check - Vehicle (Initial Inspection and Diagnostic Overview) before using the Symptom Tables in order to verify that all of the following are true:

* There are no DTCs set.
* The control modules 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 (OnStar Description and Operation).



Visual/Physical Inspection

* Inspect for aftermarket devices which could affect the operation of the Radio/Audio System. Refer to Checking Aftermarket Accessories (Component Tests and General Diagnostics).
* Inspect for 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 (Component Tests and General Diagnostics).


Symptom List

Refer to a symptom diagnostic procedure from the following list in order to diagnose the symptom:

* OnStar Global Positioning System (GPS) Data Not Current or Inaccurate (OnStar Global Positioning System (GPS) Data Not Current or Inaccurate)
* OnStar Microphone Inoperative - Caller Cannot Be Heard (OnStar Microphone Inoperative - Caller Cannot Be Heard)
* No (or Noisy) OnStar Audio (No (or Noisy) OnStar Audio)
* OnStar Button LED Inoperative (OnStar Button LED Inoperative)
* OnStar Call Center Remote Function Requests Inoperative (OnStar Call Center Remote Function Requests Inoperative)
* OnStar One or More Buttons Inoperative (OnStar One or More Buttons Inoperative)
* OnStar Symptom Diagnosis (OnStar Symptom Diagnosis)
* Unable to Contact OnStar Call Center (Unable to Contact OnStar Call Center)
* OnStar Voice Recognition Inoperative (OnStar Voice Recognition Inoperative)