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 min after turning the ignition ON for the GPS satellites to acquire vehicle signal.
- Verify the OnStar Generation you are working on by using a scan tool under Selected Vehicle Configuration/Telematics Communication Interface Control Module. Failure to use the correct document will result in incorrect diagnoses.
- Ignition OFF and all vehicle systems OFF, disconnect the cellular GPS coax cable connector at the K73 Telematics Communication Interface Control Module. It may take up to 2 min for all vehicle systems to power down.
- Connect the EL-49903-1 Test Antenna, Navn-Cell Comn to the K73 Telematics Communication Interface Control Module. Place the test antenna on the roof of the vehicle, ignition ON.
- 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.
- Go to next step: If the DTC does not set
- If the DTC sets
- Ignition OFF.
- Disconnect the EL-49903-1 Test Antenna, Navn-Cell Comn from the K73 Telematics Communication Interface Control Module
- Disconnect the GPS and cellular coax cable connector at the T4G Cellular Phone, Navigation, and Digital Radio Antenna.
Test the coax cable. Refer to Component Testing.
- 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.
- Go to next step: If the coax cable passes the test
- If the coax cable does not pass the test
- Test or replace the T4G Cellular Phone, Navigation, and Digital Radio Antenna.