Unable to Contact OnStar Call Center
Unable to Contact OnStar Call Center
Diagnostic Instructions
* Perform the Diagnostic System Check - Vehicle Diagnostic System Check - Vehicle prior to using this diagnostic procedure.
* Review Strategy Based Diagnosis Strategy Based Diagnosis for an overview of the diagnostic approach.
* Diagnostic Procedure Instructions Diagnostic Procedure Instructions provides an overview of each diagnostic category.
Circuit/System Description
The Telematics Communication Interface Control Module is a cellular device that allows the user to communicate data and voice signals over the national cellular network. When an OnStar keypress is made, the Telematics Communication Interface Control Module activates and connects the system to the cellular carriers communication system by interacting with the national cellular infrastructure. The module sends and receives all cellular communications over the cellular phone and navigation antenna and cellular antenna coax.
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.
* 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.
Reference Information
Schematic Reference
OnStar Schematics OnStar Schematics
Connector End View Reference
Component Connector End Views 1-2 Shift Solenoid (SS) Valve (M30)
Description and Operation
OnStar Description and Operation OnStar
Electrical Information Reference
* Circuit Testing Circuit Testing
* Connector Repairs Connector Repairs
* Testing for Intermittent Conditions and Poor Connections Testing for Intermittent Conditions and Poor Connections
* Wiring Repairs Wiring Repairs
Scan Tool Reference
Control Module References Control Module References for scan tool information
Special Tools
EL-49903 - GM OnStar Antenna Diagnostic Tool Kit
Circuit/System Verification
Note: The following verification requires the vehicle to be outside with an unobstructed view of the southern sky. Allow 5 minutes after turning the ignition ON for the GPS satellites to acquire vehicle signal.
1. Ignition ON.
2. Verify that DTC B2470 is not set.
• If DTC B2470 is set
Refer to DTC B2470 B2470
• If DTC B2470 is not set
3. Verify that a call can be successfully placed to the OnStar Call Center by pressing the blue OnStar button.
• If unable to connect with the OnStar Call Center.
Refer to Circuit/System Testing
• If able to connect with the OnStar Call Center
4. All OK.
Circuit/System Testing
Note:
* The vehicle may be equipped with sectioned coax. Test each section and replace only the faulty section, not the entire length of coax.
* The following verification requires the vehicle to be outside with an unobstructed view of the southern sky. Allow 5 minutes after turning the ignition ON for the GPS satellites to acquire vehicle signal.
Without Navigation Radio
1. Ignition OFF and all vehicle systems OFF, disconnect the GPS and cellular coax cable connector at the K73 Telematics Communication Interface Control Module. It may take up to 2 minutes for all vehicle systems to power down.
2. Using the EL-49903-3 kit (EL-49903-5 adapter and EL-49903-4 coax cable), connect the EL-49903 - GM OnStar antenna diagnostic tool kit to the K73 Telematics Communication Interface Control Module.
3. Ignition ON, wait 5 minutes.
4. Verify that a call can be successfully placed to the OnStar Call Center by pressing the blue OnStar button.
• If unable to connect with the OnStar Call Center
Test or replace the K73 Telematics Communication Interface Control Module.
• If able to connect with the OnStar Call Center
5. Ignition OFF, disconnect the EL-49903 - GM OnStar antenna diagnostic tool kit from the K73 Telematics Communication Interface Control Module
6. Test the coax cable between the K73 Telematics Communication Interface Control Module and the T4G Cellular Phone, Navigation, and Digital Radio Antenna. Refer to Component Testing.
• If the coax cable does not pass the test
Replace the coax cable.
• If the coax cable passes the test
7. Test or replace the T4G Cellular Phone, Navigation, and Digital Radio Antenna.
With Navigation Radio
1. Ignition OFF and all vehicle systems OFF, disconnect the GPS and cellular coax cable connector at the K73 Telematics Communication Interface Control Module. It may take up to 2 minutes for all vehicle systems to power down.
2. Using the EL-49903-3 kit (EL-49903-5 adapter and EL-49903-4 coax cable), connect the EL-49903 - GM OnStar antenna diagnostic tool kit to the K73 Telematics Communication Interface Control Module.
3. Ignition ON, wait 5 minutes.
4. Verify that a call can be successfully placed to the OnStar Call Center by pressing the blue OnStar button.
• If unable to connect with the OnStar Call Center
Test or replace the K73 Telematics Communication Interface Control Module.
• If able to connect with the OnStar Call Center
5. Ignition OFF, disconnect the EL-49903 from the K73 Telematics Communication Interface Control Module.
6. Test the coax cable between the K73 Telematics Communication Interface Control Module and the T15 Navigation Antenna Signal Splitter. Refer to Component Testing.
• If the coax cable does not pass the test
Replace the coax cable.
• If the coax cable passes the test
7. Test the coax cable between the T15 Navigation Antenna Signal Splitter and the T4G Cellular Phone, Navigation, and Digital Radio Antenna.
• If the coax cable does not pass the test
Replace the coax cable.
• If the coax cable passes the test
8. Test or replace the T15 navigation and signal splitter.
9. Verify that a call can be successfully placed to the OnStar Call Center by pressing the blue OnStar button.
• If unable to connect with the OnStar Call Center
Test or replace the T4G Cellular Phone, Navigation, and Digital Radio Antenna.
• If able to connect with the OnStar Call Center
10. All OK.
Component Testing
Caution: Refer to Test Probe Caution Test Probe Caution.
Note: Before testing the coax cable, check the cable exterior for being pinched, cut, damaged, or having loose connections at the components, which can cause reception issues.
To prevent false reading when testing the center coax terminals, use care not to ground the test probe on the outer housing/shield.
Coax Cable Test
1. Ignition OFF, disconnect the coax cable at both components.
2. Test for less than 5 ohms between the coax cable center terminal end to end.
• If 5 ohms or greater
Replace the coax cable.
• If less than 5 ohms
3. Test for greater than 5 ohms between the coax cable outer shield end to end.
• If 5 ohms or greater
Replace the coax cable.
• If less than 5 ohms
4. Test for infinite resistance between the coax cable center terminal and the coax cable outer shield.
• If less than infinite resistance
Replace the coax cable.
• If infinite resistance
5. All OK.
Repair Instructions
Perform the Diagnostic Repair Verification Verification Tests after completing the repair.
* Digital Radio, Mobile Telephone, and Vehicle Location Base Replacement Digital Radio, Mobile Telephone, and Vehicle Location Base Replacement
* Control Module References Control Module References for Telematics Communication Interface Control Module replacement, programming and setup.