B2483

DTC B2483 or B2484

Diagnostic Instructions

* Perform the Diagnostic System Check - Vehicle (Diagnostic System Check - Vehicle) prior to using this diagnostic procedure.
* Review Strategy Based Diagnosis (Strategy Based Diagnosis) for an overview of the diagnostic approach.
* Diagnostic Procedure Instructions (Diagnostic Procedure Instructions) provides an overview of each diagnostic category.

DTC Descriptors
DTC B2483 00
- Global Positioning System (GPS) Antenna Malfunction Short to Ground

DTC B2484 00
- Global Positioning System (GPS) Antenna Malfunction Open Circuit

Circuit/System Description

The communication interface module (CIM) receives information from a specific navigation antenna located on the outside of the vehicle. The navigation antenna is connected to the CIM 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 CIM detects a short to ground on the navigation antenna signal circuit.

B2484 00

The CIM detects 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 (Circuit Testing)
* Connector Repairs (Connector Repairs)
* Testing for Intermittent Conditions and Poor Connections (Testing for Intermittent Conditions and Poor Connections)
* Wiring Repairs (Wiring Repairs)

Scan Tool Reference

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

Circuit/System Testing

1. Disconnect the navigation antenna coax cable from the CIM.
2. Ignition ON, test for 4.5-5.5 V between the CIM coax cable center conductor terminal at the module and ground.

• If not within the specified range, replace the CIM.

3. Reconnect the coax cable to the CIM. Disconnect the coax cable from the navigation antenna.
4. Test for 4.5-5.5 V between the coax cable center conductor and the outer shield.

• If not within the specified range, replace the 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 (Service and Repair)
* Control Module References (Programming and Relearning) for CIM replacement, setup, and programming