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

* Radio ON.
* Battery voltage must be between 9-16 volts.



Conditions for Setting the DTC

The DTC will set when the VCIM detects a short or an open/high resistance on the navigation antenna signal circuit.


Action Taken When the DTC Sets

* The OnStar(R) status LED turns red.
* The OnStar(R) Call Center cannot locate the vehicle.



Conditions for Clearing the DTC

* The condition responsible for setting the DTC no longer exists.
* A history DTC will clear once 50 consecutive malfunction-free ignition cycles have occurred.



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)

Scan Tool Reference

Control Module References (Programming and Relearning)for scan tool information


Circuit/System Testing

1. Ignition OFF, disconnect the navigation antenna coaxial cable from the VCIM and the navigation antenna.
2. Test for less than 5 ohms of resistance between the two ends of the coax cable center conductor.

• If greater than the specified range, replace the antenna coax cable.

3. Test for less than 5 ohms of resistance between the two ends of the coax cable outer shield.

• If greater than the specified range, replace the antenna coax able.

4. Test for infinite resistance between the antenna coax center conductor and the outer shield.

• If less than the specified range, replace the antenna coax cable.

5. If all circuits test normal, replace the navigation antenna.



Repair Instructions

Perform the Diagnostic Repair Verification (Verification Tests) after completing the diagnostic procedure.

* Cellular and Navigation Antenna Assembly Replacement (Cellular and Navigation Antenna Assembly Replacement)
* Control Module References (Programming and Relearning)for VCIM replacement, setup, and programming