Diagnostic Instructions
DTC Descriptors
DTC B2483.00: GPS Sensor Circuit Low
DTC B2484.00: GPS Sensor Circuit Open
Circuit/System Description
The navigation antenna is connected to the vehicle communication interface module (VCIM) with a RG-174 coax cable. The VCIM polls the data from the navigation 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 a navigation signal. |
| • | The above conditions are present for greater than 1 second. |
Action Taken When the DTC Sets
| • | The OnStar® Call Center cannot locate the vehicle. |
| • | The OnStar® status LED turns red. |
Conditions for Clearing the DTC
| • | The VCIM detects the presence of a navigation 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
Observe that the cellular antenna and cellular antenna coupling assembly are not damaged.
| ⇒ | If it is damaged, replace the cellular antenna. |
Component Testing
Important: Using a DMM to measure the resistance of the navigation antenna coax from the center conductor to the outer shield while the antenna is still connected will damage the navigation antenna.
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 navigation antenna coax connector from the navigation antenna.
- Test for infinite resistance between the center conductor of the coax to the metal outer shield.
| ⇒ | If not specified value, replace the navigation antenna coax. |
- Test for less than 1 ohm resistance of navigation antenna coax connector from end to end.
| ⇒ | If not specified value, replace the navigation antenna coax. |
- If cellular antenna coax tests normal, test or replace the VCIM.
Repair Instructions
Perform the
Diagnostic Repair Verification
after completing the diagnostic procedure.
