B2484
DTC B2483 or B2484
Diagnostic Instructions
* Perform the Diagnostic System Check - Vehicle (Initial Inspection and Diagnostic Overview) prior to using this diagnostic procedure.
* Review Strategy Based Diagnosis (Initial Inspection and Diagnostic Overview) for an overview of the diagnostic approach.
* Diagnostic Procedure Instructions (Initial Inspection and Diagnostic Overview)provides an overview of each diagnostic category.
DTC Descriptors
DTC B2483 00
- GPS Sensor Circuit Low
DTC B2484 00
- GPS Sensor Circuit Open
Circuit/System Description
The navigation radio receives information from a specific navigation antenna located on the outside of the vehicle. The navigation antenna is connected to the vehicle communication interface module (VCIM) via a shielded coaxial cable. The antenna cable also provides a path for DC current for powering the antenna.
Conditions for Running the DTC
* Ignition is in the RUN or ACC position.
* System voltage is between 9.5 volts and 15.5 volts.
* 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(R) Call Center cannot locate the vehicle.
* The OnStar(R) 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.
Reference Information
Schematic Reference
OnStar Schematics (OnStar Schematics)
Connector End View Reference
Component Connector End Views (Connector Views)
Description and Operation
OnStar Description and Operation (OnStar Description and Operation)
Electrical Information Reference
* Circuit Testing (Component Tests and General Diagnostics)
* Connector Repairs (Component Tests and General Diagnostics)
* Testing for Intermittent Conditions and Poor Connections (Component Tests and General Diagnostics)
* Wiring Repairs (Component Tests and General Diagnostics)
Circuit/System 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.
1. Ignition OFF, disconnect the cellular antenna coax from the VCIM module and the cellular antenna.
2. 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.
3. 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.
4. Test for infinite resistance between the antenna coax center terminal and ground.
• If less than the specified value, replace the antenna coax
5. Test for infinite resistance between the antenna coax outer shield and ground.
• If less than the specified value, replace the antenna coax
6. Test for less than 5 ohms of resistance at the cellular antenna coax center terminal from end to end.
• If greater than specified value, replace the cellular antenna coax cable.
7. Test for less than 5 ohms of resistance at the cellular antenna coax outer shield from end to end.
• If greater than specified value, replace the cellular antenna coax cable.
8. 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.
9. If coax cable tests normal, test or replace the cellular antenna.
Repair Instructions
Perform the Diagnostic Repair Verification (Verification Tests) after completing the diagnostic procedure.
* Mobile Telephone Digital Antenna Replacement (Mobile Telephone Digital Antenna Replacement)
* Control Module References (Programming and Relearning)for VCIM replacement, setup, and programming