Circuit/System Testing

without Navigation System

1. Ignition OFF, disconnect the GPS and cellular coax cable connector at the K73 Telematics Communication Interface Control Module.
2. Using the EL-49903  OnStar Antenna Diagnostic Tool Kit , connect the EL-49903-3 antenna to the K73 Telematics Communication Interface Control Module. Place the test antenna on the roof of the vehicle, ignition ON.
3. Verify that an OnStar advisor can locate the vehicle after performing a blue button press.
   • If the advisor can not locate the vehicle 

     Replace the K73 Telematics Communication Interface Control Module.

   • If the advisor can locate the vehicle 
4. Ignition OFF, disconnect the EL-49903  GM OnStar antenna diagnostic tool kit from the K73 Telematics Communication Interface Control Module
5. Disconnect the K73 Telematics Communication Interface Control Module coax at the T4G Cellular Phone, Navigation, and Digital Radio Antenna.
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 System

NOTE:

Perform the Circuit/System Verification before proceeding with Circuit/System Testing.

1. Ignition OFF, disconnect the coax cable at the T15 Navigation Antenna Signal Splitter.
2. Connect the EL-49903  OnStar Antenna Diagnostic Tool Kit to the T15 Navigation Antenna Signal Splitter. Place the test antenna on the roof of the vehicle, ignition ON.
3. Verify that an OnStar advisor can not locate the vehicle after performing a blue button press.
   • If the advisor can locate the vehicle 
   1. Ignition OFF, disconnect the coax cable at the T4G Cellular Phone, Navigation, and Digital Radio Antenna.
   2. Test the coax cable between the T15 Navigation Antenna Signal Splitter 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
   3. Replace the T4G Cellular Phone, Navigation, and Digital Radio Antenna.
   • If the advisor can not locate the vehicle 
4. Ignition OFF, disconnect the GPS and cellular coax cable connector at the K73 Telematics Communication Interface Control Module.
5. Connect the EL-49903  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.
6. Verify that an OnStar advisor can locate the vehicle after performing a blue button press.
   • If the advisor can not locate the vehicle 

     Replace the K73 Telematics Communication Interface Control Module.

   • If the advisor can locate the vehicle 
7. Ignition OFF.
8. Test the coax cable between the T15 Navigation Antenna Signal Splitter and the K73 Telematics Communication Interface Control Module. Refer to Component Testing .
   • If the coax cable does not pass the test 

     Replace the coax cable.

   • If the coax cable passes the test 
9. Ignition OFF, disconnect the GPS coax cable at the K74 Human Machine Interface Control Module.
10. Connect the EL-49903  OnStar Antenna Diagnostic Tool Kit to the K74 Human Machine Interface Control Module and place the test antenna on the roof of the vehicle.
11. Ignition ON.
12. Verify that the NO GPS symbol/message is not displayed on the P17 Display Module.
    • If the NO GPS symbol/message is displayed 

      Replace the K74 Human Machine Interface Control Module

    • If the NO GPS symbol/message is not displayed 
13. Ignition OFF.
14. Test the coax cable between the T15 Navigation Antenna Signal Splitter and the K74 Human Machine Interface Control Module. Refer to Component Testing .
    • If the coax cable does not pass the test 

      Replace the coax cable.

    • If the coax cable passes the test 
15. Test or replace the T15 Navigation Antenna Signal Splitter.