For 1990-2009 cars

## DTC B2462 Navigation Radio

### 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) Short to Ground
DTC B2462 04: Global Positioning System (GPS) Open Circuit

### Circuit Description

The global positioning system (GPS) antenna is connected to the navigation radio by a 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 between 9-16 volts

• | The navigation radio tests the GPS antenna every 10 seconds

### Conditions for Setting the DTC

#### B2462 02

The navigation radio detects a short to ground in the GPS antenna signal circuit.

#### B2462 04

The navigation radio detects an open/high resistance in the GPS antenna signal circuit.

### Actions Taken When the DTC Sets

• | The radio uses the last reported position and the vehicle speed signal to calculate the vehicle position.

• | Route guidance may be inaccurate.

• | Turn by turn navigation may be inaccurate or inoperative.

### 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

Radio/Navigation System Schematics

#### Connector End View Reference

Component Connector End Views

#### 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

Important: The global positioning system (GPS) requires a clear line of sight to the sky to operate properly. In most cases the GPS will not have reception near tall buildings or inside structures.

1. Ignition OFF, disconnect the GPS antenna coax cable from the navigation radio.
2. Ignition ON, test for 4.5-5.5 volts between the coax cable connection center conductor at the radio and ground.

⇒ | If not within the specified range, replace the radio.

3. If all circuits test normal, replace the GPS antenna.

### Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

• | Electronic Navigation Antenna Replacement

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

## DTC B2462 Communication Interface Module

### 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.

• | Radio Antenna Base Replacement

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