For 1990-2009 cars

### Diagnostic Instructions

• | Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure.

• | Review Strategy Based Diagnosis for an overview of the diagnostic approach.

• | Diagnostic Procedure Instructions provides an overview of each diagnostic category.

### DTC Descriptors

DTC B2462 02: Global Positioning System (GPS) Antenna Malfunction Short to Ground
DTC B2462 04: 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

#### B2462 02

The CIM detects a short to ground on the navigation antenna signal circuit.

#### B2462 04

The CIM detects an open/high resistance on the navigation antenna signal circuit.

### Action Taken When the DTC Sets

• | The OnStar® status LED turns red.

• | The OnStar® 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

#### Connector End View Reference

Component Connector End Views

#### Description and Operation

OnStar Description and Operation

#### Electrical Information Reference

• | Circuit Testing

• | Connector Repairs

• | Testing for Intermittent Conditions and Poor Connections

• | Wiring Repairs

#### Scan Tool Reference

Control Module References 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 after completing the diagnostic procedure.

• | Cellular and Navigation Antenna Assembly Replacement

• | Control Module References for CIM replacement, setup, and programming