Unable to Contact OnStar Call Center

Unable to Contact OnStar Call Center

Diagnostic Instructions

* Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure. Initial Inspection and Diagnostic Overview
* Review Strategy Based Diagnosis for an overview of the diagnostic approach.
* Diagnostic Procedure Instructions provides an overview of each diagnostic category.

Diagnostic Aids

* The customer concern may have been due to a lack of cellular service in a given area. A failure in the National Cellular Network infrastructure at the time of the customers failed connection that has since been repaired may also have been the cause.
* If an OnStar(R) emergency call is able to successfully connect the vehicle to the OnStar(R) Call Center when an OnStar(R) Call Center button press is not, there may be a failure in the ability of the OnStar(R) system in the vehicle to be recognized by the local cellular carrier.
* If the prompt "OnStar(R) request ended" is heard, without pressing the white dot button at the end of the OnStar(R) keypress, the OnStar(R) system at one time has made a successful cellular connection, but was unable to complete the call. If repeated calls are placed with this result, contact General Motors Technical Assistance Center.

Circuit/System Verification

Important:
* It is important to have the vehicle in an open outside area where a cellular call can be successfully placed and GPS data can be received from satellites.

* Placing an emergency call to the OnStar(R) Call Center should only be made if the diagnosis of the system leads to step 3. Immediately after an OnStar(R) advisor picks up the call, they should be told that this call is for diagnostic purposes only and there is no emergency.

1. Press the OnStar(R) Call Center button. Verify a connection is not made with the OnStar(R) Call Center.

• If a connection is made with the OnStar(R) Call Center, refer to Diagnostic Aids.

2. Listen for other tones or cellular messages rather than the normal progression tones or the Unable to Contact OnStar(R) prompt.

• If no other tones or cellular messages are heard other than the normal progression tones or the Unable to Contact OnStar(R) prompt, go to Component Testing.

3. Record all messages heard from the OnStar(R) Call Center button press.
4. Press the OnStar(R) emergency button. Verify a connection to the OnStar(R) Call Center is made within 10 minutes.

• If a connection is not made within specified time, go to Component Testing.

5. Hear all messages during the course of the tests available, use the scan tool to access the STID, ESN and Transceiver I.D. and contact the General Motors Technical Assistance Center.

Component Testing

Important: The vehicle may be equipped with sectioned coax cable. Test each section and replace only the faulty section, not the entire length or coax.

1. Ignition OFF, disconnect the coax harness connectors at the VCIM and the cellular antenna.
2. Test for less than 5 ohms between the two ends of the coax cable center conductor.

• If greater than the specified range, replace the cellular antenna coax cable.

3. Test for less than 5 ohms between the two ends of the coax cable outer shield.

• If greater than the specified range, replace the cellular antenna coax cable.

4. Test for infinite resistance between the coax center conductor and the outer shield.

• If less than the specified range, replace the cellular antenna coax cable.

5. Connect the coax harness connector at the VCIM.
6. Ignition ON, test for 4.0-5.5 volts between the coax center conductor and the outer shield.

• If not within the specified range, replace the VCIM.

7. If all circuits test normal, replace the cellular antenna.

Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure. Verification Tests

* Cellular Communications/Digital Radio Antenna Replacement