Buick Regal: No Global Positioning System (GPS) Reception (without IO5/IO6)

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.
• Refer to Diagnostic Procedure Instructions for an overview of each diagnostic category.

DTC Descriptors

DTC B2462 02

Global Positioning System (GPS) Signal Short to Ground

DTC B2462 04

Global Positioning System (GPS) Signal Open Circuit

Circuit/System Description

The Telematics Communication Interface Control Module receives information from the GPS antenna located on the outside of the vehicle. The GPS antenna is connected to the Telematics Communication Interface Control Module via a shielded coaxial cable. The telematics communication interface control module supplies 5 V through the coax cable to power the internal antenna amplifier.

Conditions for Running the DTC

• Ignition is in the RUN or ACC position.
• System voltage is between 9.5 V and 15.5 V.
• The above conditions are present for greater than 1 second.

Conditions for Setting the DTC

B2462 02

The Telematics Communication Interface Control Module detects a short to ground on the GPS antenna signal circuit.

B2462 04

The Telematics Communication Interface Control Module detects an open/high resistance on the GPS 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 K73 Telematics Communication Interface Control Module detects the presence of a GPS antenna.
• A history DTC will clear once 50 consecutive malfunction-free ignition cycles have occurred.

Reference Information

Schematic Reference

OnStar/Telematics Wiring Schematics

Connector End View Reference

Component Connector End View Index

Description and Operation

OnStar Description and Operation (UE1 with IOB/IO6) , OnStar Description and Operation (UI3) , or OnStar Description and Operation (UE1 without IOB/IO6).

Electrical Information Reference

• Refer to Circuit Testing
• Refer to Connector Repairs
• Refer to Testing for Intermittent Conditions and Poor Connections
• Refer to Wiring Repairs

Scan Tool Reference

Control Module References for scan tool information.

Special Tools

EL-49903 GM OnStar Antenna Diagnostic Tool Kit

Circuit/System Testing

1. Ignition OFF/vehicle OFF, disconnect the GPS coax cable connector at the K73 Telematics Communication Interface Control Module.

2. Connect the EL-49903-1 OnStar Test Antenna, Navn-Cell Comn to the K73 Telematics Communication Interface Control Module. Place the test antenna on the roof of the vehicle, ignition ON/vehicle in Service Mode.

3. Verify DTC B2462 is not set or that the OnStar advisor can locate the vehicle.

• If DTC B2462 is set or the advisor can not locate the vehicle

Replace the K73 Telematics Communication Interface Control Module.

• Go to next step: If DTC B2462 is not set or that the OnStar advisor can locate the vehicle.

4. Ignition OFF/vehicle OFF, disconnect the EL-49903-1 OnStar Test Antenna, Navn-Cell Comn from the K73 Telematics Communication Interface Control Module 5. Disconnect the GPS coax cable at the T2RR Antenna - Roof Rear.

6. Test the coax cable between the K73 Telematics Communication Interface Control Module and the T2RR Antenna - Roof Rear. Refer to Component Testing.

• If the coax cable does not pass the test

Replace the coax cable.

• Go to next step: If the coax cable passes the test

7. Test or replace the T2RR Antenna - Roof Rear.

Component Testing

CAUTION: Refer to Test Probe Caution

NOTE:

• Before testing the coax cable, check the cable exterior for being pinched, cut, damaged, or having loose connections at the components, which can cause reception issues.
• To prevent false readings when testing the center coax terminals, use care not to ground the test probe on the outer housing/shield.

Coax Cable Test

1. Ignition OFF, disconnect the coax cable at both components.

2. Test for less than 5 Ω between the coax cable center terminal end to end.

• If 5 Ω or greater

Replace the coax cable.

• Go to next step: If less than 5 Ω

3. Test for greater than 5 Ω between the coax cable outer shield end to end.

• If 5 Ω or greater

Replace the coax cable.

• Go to next step: If less than 5 Ω

4. Test for infinite resistance between the coax cable center terminal and the coax cable outer shield.

• If less than infinite resistance

Replace the coax cable.

• Go to next step: If infinite resistance

5. All OK.

Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

• Refer to High Frequency Antenna Replacement
• Refer to Control Module References for Telematics Communication Interface Control Module replacement, programming and setup.

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