Buick Regal: No Global Positioning System (GPS) Reception (IO5/IO6 without UE1)

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

Global Positioning System Signal

For symptom byte information refer to Symptom Byte List.

Circuit Description

The navigation antenna is connected to the human machine interface control module by a shielded coaxial cable. The human machine interface control module supplies 5 V through the coax cable to power the internal antenna amplifier.

Conditions for Running the DTC

• Radio On.
• System voltage is greater than 9 V and less than 16 V.
• The human machine interface control module tests the GPS antenna every 10 seconds.

Conditions for Setting the DTC

B2462 01

The human machine interface control module detects a short to B+ on the GPS antenna signal circuit.

B2462 02

The human machine interface control module detects a short to ground on the GPS antenna signal circuit.

B2462 04

The human machine interface control module detects an open/high resistance on the GPS antenna signal circuit.

Actions Taken When the DTC Sets

• The human machine interface control module 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.

Diagnostic Aids

The navigation antenna requires a clear line of sight to the sky to operate properly. The GPS may have limited, intermittent, or no reception near tall buildings or inside structures.

Reference Information

Schematic Reference

Radio/Navigation System Wiring Schematics (IOB) , Radio/Navigation System Wiring Schematics (IOR) or Radio/Navigation System Wiring Schematics (IO5/IO6) , or Radio/Navigation System Wiring Schematics (IOS/IOT).

Connector End View Reference

Component Connector End View Index

Description and Operation

Radio/Audio System Description and Operation (IO6) , Radio/Audio System Description and Operation (IOB) , or Radio/Audio System Description and Operation (IOS/IOT/IOU).

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 OnStar Antenna Diagnostic Tool Kit

Circuit/System Testing

1. Ignition OFF/vehicle OFF, disconnect the navigation antenna coax cable connector at the K74 Human Machine Interface Control Module. Connect the EL-49903 GM OnStar antenna diagnostic tool kit to the K74 Human Machine Interface Control Module, place the test antenna on the roof of the vehicle.

2. Ignition ON/vehicle in Service Mode, infotainment system ON, navigation selected.

3. Verify DTC B2462 is not set or the NO GPS symbol is not displayed on the information display.

• If DTC B2462 is set or if the NO GPS symbol is displayed

Replace the K74 Human Machine Interface Control Module.

• Go to next step: If DTC B2462 is not set or the NO GPS symbol is not displayed

4. Ignition OFF/vehicle OFF, disconnect the radio navigation coax cable at the.

5. Verify the radio navigation coax cable passes the coax cable component test. 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

6. 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 reading 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 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 less 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 human machine interface control module replacement, programming, and setup.

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