Circuit/System Testing
WARNING: This page is about a different car, the 2020 Cadillac CT4. However, it is still accessible from the selected car via links, so may be relevant.
- Ignition OFF, disconnect the GPS coax cable connector at the A11 Radio.
- Connect the EL-49903-1 OnStar Test Antenna, Navn-Cell Comn to the A11 Radio. Place the test antenna on the roof of the vehicle, ignition ON/vehicle in Service Mode.
- Verify DTC B1784 is not set or the vehicle location from the GPS is correct.
- If DTC B1784 is set or the vehicle location from the GPS is not correct
Replace the A11 Radio.
- Go to next step: If DTC B1784 is not set or the vehicle location from the GPS is correct
- If DTC B1784 is set or the vehicle location from the GPS is not correct
- Ignition OFF, disconnect the EL-49903-1 OnStar Test Antenna, Navn-Cell Comn from the A11 Radio.
- Disconnect the GPS coax cable at the T4P High Frequency Antenna.
- Test the coax cable between the A11 Radio and the T4P High Frequency 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 T4P High Frequency Antenna.