Circuit/System Testing

IMPORTANT:

The global positioning system (GPS) requires a clear line of sight to the sky to operate properly. In most cases the GPS will not have reception near tall buildings or inside structures.

Ignition OFF, disconnect the GPS antenna coax cable at the A11 Radio.
Connect the EL-49903-1 OnStar test antenna to the A11 Radio. Place the test antenna on the roof of the vehicle, ignition ON.
Verify DTC B2462 is not set or that the NO GPS symbol/message is not displayed on the navigation radio.
- If DTC B2462 is set or the NO GPS symbol/message is displayed
  Replace the A11 Radio.
- Go to next step: If DTC B2462 is not set or the NO GPS symbol/message is not displayed.
Ignition OFF, disconnect the EL-49903-1 OnStar test antenna from the A11 Radio
Disconnect the GPS coax cable at the T4P Electronic Navigation Antenna.
Test the coax cable between the A11 Radio and the T4P Electronic Navigation 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
Test or replace the T4P Electronic Navigation Antenna.