B2483

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
- GPS Sensor Circuit Low

DTC B2484
- GPS Sensor Circuit Open




Circuit/System Description

The vehicle communication interface module (VCIM) receives information from a specific GPS antenna located on the outside of the vehicle. The GPS antenna is connected to the 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.
* Battery voltage is between 9-16 volts.



Conditions for Setting the DTC

B2483 00

The VCIM detects a short to ground on the GPS antenna signal circuit.

B2484 00

The VCIM detects an open/high resistance on the GPS 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)



Circuit/System Testing

1. Disconnect the harness connector at the radio antenna.
2. Ignition OFF, test for less than 10 ohms between the terminal 4 outer shield and ground.

• If greater than the specified range, test the antenna coax shield for an open/high resistance. If the coax tests normal, replace the VCIM.

3. Ignition ON, test the terminal 4 center terminal for 4.5-5.5 volts.

• If greater than the specified range, test the antenna coax center terminal for a short to voltage. If the coax tests normal, replace the VCIM.
• If less than the specified range, test the antenna coax center terminal for a short to ground or an open/high resistance. If the coax tests normal, replace the VCIM.

4. If all circuits test normal, replace the antenna.



Repair Instructions

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

* Radio Antenna Replacement (L48) (Radio Antenna Replacement (L48))Radio Antenna Replacement (L08) (Radio Antenna Replacement (L08))
* Antenna Cable Replacement (Coupe) (Antenna Cable Replacement (Coupe))Antenna Cable Replacement (Sedan) (Antenna Cable Replacement (Sedan))
* Control Module References (Programming and Relearning) for VCIM replacement, setup, and programming