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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 coax cable passes the test 
  7. Test or replace the T4D Cellular Phone 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. 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.
  5. Disconnect the EL-49903  GM OnStar antenna diagnostic tool kit from the K73 Telematics Communication Interface Control Module
  6. 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.
  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. Ignition OFF.
    2. 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, test or replace the K73 Telematics Communications Interface Control Module.
    • If greater than 5.5 V 
    1. Ignition OFF.
    2. 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, test or replace the K73 Telematics Communications Interface Control Module.
    • If between 4.5 - 5.5 V 
  8. Ignition OFF, connect the coax cable to the T15 Navigation Antenna Signal Splitter and disconnect the coax cable from the T4D Cellular Phone and Digital Radio Antenna, ignition ON.
  9. Test for 4.5 - 5.5 V between the coax cable center conductor and the outer shield.
    • If less than 4.5 V 
    1. Ignition OFF.
    2. 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, test or replace the T15 Navigation Antenna Signal Splitter.
    • If greater than 5.5 V 
    1. Ignition OFF.
    2. 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, test or replace the T15 Navigation Antenna Signal Splitter.
    • If between 4.5 - 5.5 V 
  10. Test or replace the T4D Cellular Phone and Digital Radio Antenna.
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