Circuit/System Testing

Without Navigation Radio

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 min after turning the Vehicle in Service Mode for the GPS satellites to acquire vehicle signal.
2. Vehicle OFF and all vehicle systems OFF, disconnect the GPS and cellular coax cable connector at the K73 Telematics Communication Interface Control Module.
3. 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, vehicle in Service Mode.
4. Vehicle in Service Mode.
5. 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 
6. Vehicle OFF.
7. Disconnect the EL-49903  GM OnStar antenna diagnostic tool kit from the K73 Telematics Communication Interface Control Module
   • 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 T4G Cellular Phone, Navigation, and Digital Radio Antenna.

With Navigation Radio

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 min after turning the Vehicle in Service Mode for the GPS satellites to acquire vehicle signal.
2. Vehicle OFF and all vehicle systems OFF, disconnect the GPS and cellular coax cable connector at the K73 telematics communications interface control module.
3. 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.
4. Vehicle in Service Mode.
5. 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 
6. Vehicle OFF, Disconnect the EL-49903  GM OnStar antenna diagnostic tool kit from the K73 Telematics Communication Interface Control Module.
7. Connect the coax cable to the K73 Telematics Communication Interface Control Module and disconnect the coax cable from the T15 Navigation Signal Splitter.
8. Vehicle in Service Mode.
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. Vehicle OFF.
   2. Test the coax cable. Refer to Component Testing below.
      • 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. Vehicle OFF.
   2. Test the coax cable. Refer to Component Testing below.
      • 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 
10. Vehicle OFF.
11. Vehicle OFF, connect the coax cable to the T15 Navigation Antenna Signal Splitter and disconnect the coax cable from the T4G Cellular Phone, Navigation, and Digital Radio Antenna, vehicle in Service Mode.
12. Test for 4.5-5.5 V between the coax cable center conductor and the outer shield.
    • If less than 4.5 V 
    1. Vehicle OFF.
    2. Test the coax cable. Refer to Component Testing below.
       • 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. Vehicle OFF.
    2. Test the coax cable. Refer to Component Testing below.
       • 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 
13. Test or replace the T4G Cellular Phone, Navigation, and Digital Radio Antenna.