Chevrolet Trax: Unable to contact onstar call center

Diagnostic Instructions

• Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure.
• Review Strategy Based Diagnosis for an overview of the diagnostic approach.
• 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 emergency call is able to successfully connect the vehicle to the OnStar Call Center when an OnStar Call Center button press is not, there may be a failure in the ability of the OnStar system in the vehicle to be recognized by the local cellular carrier.
• If the prompt "OnStar request ended" is heard, without pressing the white dot button at the end of the OnStar keypress, the OnStar 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/Telematics Schematics (Encore), OnStar/Telematics Schematics (Trax)

Connector End View Reference

WIRING SYSTEMS AND POWER MANAGEMENT - COMPONENT CONNECTOR END VIEWS - INDEX - ENCORE WIRING SYSTEMS AND POWER MANAGEMENT - COMPONENT CONNECTOR END VIEWS - INDEX - TRAX

Description and Operation

OnStar Description and Operation

Electrical Information Reference

• Circuit Testing
• Connector Repairs
• Testing for Intermittent Conditions and Poor Connections
• Wiring Repairs

Scan Tool Reference

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

• 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 bulletin PIC4310.

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.

   Place the test antenna on the roof of the vehicle, ignition ON.

3. Verify the DTC does not set while operating the vehicle within the conditions for running the DTC.

• If the DTC sets

Replace the K73 Telematics Communications Interface Control Module.

• If the DTC does not set

4. Ignition OFF.
5. Disconnect the EL-49903 GM OnStar antenna diagnostic tool kit from the K73 Telematics Communication Interface Control Module
6. Test the coax cable. Refer to Component Testing.

• If the coax cable does not pass the test

Replace the coax cable.

• If the DTC does not set

4. Ignition OFF.
5. Disconnect the EL-49903 GM OnStar antenna diagnostic tool kit from the K73 Telematics Communication Interface Control Module
6. Test the coax cable. 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 T4E Cellular Phone and Navigation 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.

   Place the test antenna on the roof of the vehicle, ignition ON.

3. Verify the DTC does not set while operating the vehicle within the conditions for running the DTC.

• If the DTC sets

Replace the K73 Telematics Communication Interface Control Module.

• If the DTC does not set

4. Ignition OFF, connect the coax cable to the K73 Telematics Communications Interface Control Module and disconnect the coax cable from the T15 Navigation Antenna Signal Splitter, ignition ON.
5. Test for 4.5-5.5 V between the coax cable center conductor and the outer shield.

If less than 4.5 V

1. Test the coax cable between the K73 Telematics Communications Interface Control Module and the T15 Navigation Antenna Signal Splitter. Refer to Component Testing.

• If the coax does not successfully pass the component test, replace the coax.
• If the coax successfully passes the coax test, replace the K73 Telematics Communications Interface Control Module.
• If greater than 5.5 V

1. Test the coax cable between the K73 Telematics Communications 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.
• If the coax cable passes the test, replace the K73 Telematics Communications Interface Control Module.
• If between 4.5-5.5 V

6. Ignition OFF, connect the coax cable to the T15 Navigation Antenna Signal Splitter and disconnect the coax cable from the T4E Cellular Phone and Navigation Antenna, ignition ON.
7. Test for 4.5-5.5 V between the coax cable center conductor and the outer shield.

If less than 4.5 V

1. Test the coax cable between the T15 Navigation Antenna Signal Splitter and the T4E Cellular Phone and Navigation Antenna. Refer to Component Testing.

• If the coax does not successfully pass the component test, replace the coax.
• If the coax successfully passes the coax test, test or replace the T15 Navigation Antenna Signal Splitter
• If greater than 5.5 V

1. Phone and Navigation Antenna. Refer to Component Testing.

• If the coax cable does not pass the test, replace the coax.
• If the coax cable passes the test, test or replace the T15 Navigation Antenna Signal Splitter
• If between 4.5-5.5 V

8. Test or replace the T4E Cellular Phone and Navigation Antenna.

Component Testing

CAUTION: Refer to 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 readings 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 after completing the repair.

• Navigation Signal Splitter Replacement (Encore)
• Radio Antenna Base Replacement
• Control Module References for telematics communication interface control module replacement, programming and setup.

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