B2483

DTC B2483 or B2484

Diagnostic Instructions

* Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure. Initial Inspection and Diagnostic Overview
* Review Strategy Based Diagnosis for an overview of the diagnostic approach.
* 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.
* 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

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.

Circuit/System Testing

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

• If the reading is 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 volts between the coax cable center conductor and the outer shield.

• If the reading is 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 after completing the diagnostic procedure. Verification Tests

* Mobile Telephone Digital Antenna Replacement