Circuit/System Testing
WARNING: This page does not describe the selected car, but rather 8 other vehicles, including the 2008 GMC Yukon XL, 2008 GMC Yukon, 2008 Chevrolet Tahoe, 2008 Chevrolet Suburban, and 2008 Chevrolet Avalanche. 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.
- 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.
- Clear the DTCs and operate the vehicle within the conditions for running the DTC. Verify DTC B2470 does not set.
- If the DTC sets, replace the CIM.