Diagnostic Instructions
DTC Descriptor
DTC B2470 00: Cellular Phone Antenna Circuit Malfunction
Circuit/System Description
The cellular antenna is connected to the vehicle communication interface module (VCIM) with a RG-58 coax cable. The VCIM polls the data from the cellular antenna once every second.
Conditions for Running the DTC
| • | The ignition must be in the RUN or ACC position. |
| • | The system voltage is at least 9.5 volts and no more than 15.5 volts. |
| • | All the above conditions are present for greater than 1 second. |
Conditions for Setting the DTC
| • | The VCIM does not detect the presence of a cellular antenna. |
| • | The above conditions are present for greater than 1 second. |
Action Taken When the DTC Sets
| • | The vehicle is unable to connect to the OnStar® Call Center. |
| • | The OnStar® status LED turns red. |
Conditions for Clearing the DTC
| • | The VCIM detects the presence of a cellular antenna. |
| • | A history DTC clears after 50 malfunction-free ignition cycles. |
| • | The VCIM receives the clear DTC command from the scan tool. |
Reference Information
Schematic Reference
OnStar Schematics
Connector End View Reference
Entertainment/Communication Connector End Views
Description and Operation
OnStar Description and Operation
Electrical Information Reference
Circuit/System Verification
Verify that the cellular antenna and cellular antenna coupling assembly are not damaged.
| ⇒ | If the antenna assembly is damaged, replace the cellular antenna. |
Component Testing
Important: The vehicle may be equipped with sectioned coax. Test each section and replace only the faulty section, not the entire length of coax.
- Disconnect the cellular antenna coax connector at the VCIM .
- Test for infinite resistance between the center conductor and the outer metal shield of the cellular antenna coax cable.
| ⇒ | If meter does not read infinite, replace the cellular antenna coax cable. |
- Test for less than 1 ohm of resistance at the cellular antenna coax connector from end to end.
| ⇒ | If greater than specified value, replace the cellular antenna coax cable. |
- If coax cable tests normal, test or replace the VCIM.
Repair Instructions
Perform the
Diagnostic Repair Verification after completing the diagnostic procedure.
