Circuit/System Testing
WARNING: This page is about a different car, the 2010 Cadillac STS. However, it is still accessible from the selected car via links, so may be relevant.
- Ignition OFF, disconnect the cellular antenna coax from the CIM module and the cellular antenna.
- Connect the EL-49903 to the CIM, place the test antenna on the roof of the vehicle.
- Ignition ON, clear the DTCs and operate the vehicle within the conditions for running the DTC. Verify B2470 does not set
- if the DTC sets, replace the CIM.
- Ignition ON, test for less than 1 volt between the antenna coax center terminal and ground.
- If greater than the specified range, replace the antenna coax.
- Ignition ON, test for less than 1 volt between the antenna coax outer shield and ground.
- If greater than the specified range, replace the antenna coax.
- Test for infinite resistance between the antenna coax center terminal and ground.
- If less than the specified value, replace the antenna coax
- Test for infinite resistance between the antenna coax outer shield and ground.
- If less than the specified value, replace the antenna coax
- Test for less than 5 ohms at the cellular antenna coax center terminal from end to end.
- If greater than specified value, replace the cellular antenna coax cable.
- Test for less than 5 ohms at the cellular antenna coax outer shield from end to end.
- If greater than specified value, replace the cellular antenna coax cable.
- Test for infinite resistance between the antenna coax center terminal and the outer shield.
- If less than specified value, replace the cellular antenna coax cable.
- If coax cable tests normal, replace the cellular antenna.
NOTE:
The vehicle may be equipped with sectioned coax. Test each section and replace only the faulty section, not the entire length of coax.