Circuit/System Testing
WARNING: This page is about a different car, the 2008 Cadillac STS. However, it is still accessible from the selected car via links, so may be relevant.
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 coax harness connectors at the navigation radio and the GPS antenna.
- Test for less than 5 ohms of resistance between the two ends of the coax cable center conductor.
- If greater than the specified range, replace the GPS antenna coax cable.
- Test for less than 5 ohms of resistance between the two ends of the coax cable outer shield.
- If greater than the specified range, replace the GPS antenna coax cable.
- Test for infinite resistance between the coax center conductor and the outer shield.
- If less than the specified range, replace the GPS antenna coax cable.
- Connect the coax harness connector at the navigation radio.
- Ignition ON, test for 4.0- 5.5 volts between the coax center conductor and the outer shield.
- If not within the specified range, replace the navigation radio.
- If all circuits test normal, replace the GPS antenna.