Buick Regal: No Global Positioning System (GPS) Reception (IO5/IO6 with 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 02

Global Positioning System Short to Ground

DTC B2462 04

Global Positioning System Open

Circuit/System Description

The navigation antenna is connected to the Telematics Communication Interface Control Module. The module supplies 5 V to the antenna to power the internal amplifier through the center conductor of the antenna coax cable.

When the vehicle is equipped with the optional navigation system, a Navigation Antenna Signal Splitter is installed to distribute the navigation signal to both the Telematics Communication Interface Control Module and the Human Machine Interface Control Module. The Human Machine Interface Control Module supplies 5 V through the coax cable to power the Navigation Antenna Signal Splitter.

Conditions for Running the DTC

• Radio On.
• System voltage is greater than 9 V and less than 16 V.
• The navigation system/telematics communication interface control module tests the GPS antenna every 10 s.

Conditions for Setting the DTC

B2462 02

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

B2462 04

The Telematics Communication Interface Control Module or Human Machine Interface Control Module detects a open/high resistance on the GPS antenna signal circuit.

Action Taken When the DTC Sets

• The Telematics Communication Interface Control Module or 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 scan tool Telematics Communication Interface Control Module GPS signal parameter will display a Yes or No dependent upon whether or not the module sees an increment of the seconds transmitted by GPS signals to the Telematics Communication Interface Control Module. Upon entering this screen, the GPS signal title will initially display Yes, regardless of the presence of time increment, for at least 2 seconds, while the algorithm in the scan tool determines the status of the clock. If increment is found, Yes is continually displayed. If the clock remains static, No is displayed. The scan tool looks for increment every second, regardless of current display.
• Inaccurate or aged GPS position concerns which are no longer present may have been due to the temporary loss of GPS signal reception by the vehicle. Conditions such as tunnels or parking structures will restrict the cellular phone and navigation antenna from a clear view of the satellites in the sky and may have caused this temporary data loss.
• The 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.

Reference Information

Schematic Reference

• Refer to OnStar/Telematics Wiring Schematics.
• Refer to 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

• Refer to OnStar Description and Operation (UE1 with IOB/IO6) , OnStar Description and Operation (UI3) , or OnStar Description and Operation (UE1 without IOB/IO6)
• Refer to 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 Verification

NOTE: The following verification requires the vehicle to be outside with an unobstructed view of the southern sky. Allow 5 minutes after turning the ignition ON for the vehicle to acquire the GPS satellites signal.

1. Ignition ON/vehicle in Service Mode.

2. Verify that DTC B2462 is not set in the Telematics Communication Interface Control Module.

• If DTC B2462 is set in the Telematics Communication Interface Control Module and the vehicle is not equipped with a navigation system

Refer to Circuit/System Testing Without Navigation System.

• If DTC B2462 is set in the Telematics Communication Interface Control Module and the vehicle is equipped with a navigation system

Refer to Circuit/System Testing With Navigation System.

• Go to next step: If DTC B2462 is not set in the Telematics Communication Interface Control Module

3. Verify an OnStar advisor can locate the vehicle after performing a blue button press.

• If the advisor can not locate the vehicle and the vehicle is not equipped with a navigation system

Refer to Circuit/System Testing Without Navigation System

• If the advisor can not locate the vehicle and the vehicle is equipped with a navigation system

Refer to Circuit/System Testing With Navigation System.

• Go to next step: If the advisor can locate the vehicle

4. Verify DTC B2462 is not set in the Human Machine Interface Control Module.

• If DTC B2462 is set in the Human Machine Interface Control Module

Refer to Step 9 of Circuit/System Testing With Navigation System.

• Go to next step: If DTC B2462 is not set in the Human Machine Interface Control Module

5. Verify that the NO GPS symbol/message is not displayed on the radio display.

• If the NO GPS symbol/message is displayed

Refer to Step 9 of Circuit/System Testing With Navigation System.

• Go to next step: If the NO GPS symbol/message is not displayed

6. All OK.

Circuit/System Testing

Without Navigation System

NOTE: You must perform the Circuit/System Verification before proceeding with Circuit/System Testing.

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

2. Attach both leads of the EL-49903 - 1 OnStar test antenna to the EL-49903 - 5 combiner. Using the EL-49903 - 6 coax cable attach the grey connector to the combiner and the brown connector to the K73 Telematics Communication Interface Control Module. Place the test antenna on the roof of the vehicle, ignition ON.

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 the advisor can locate the vehicle

4. 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

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

With Navigation System

NOTE: You must perform the Circuit/System Verification before proceeding with Circuit/System Testing.

1. Ignition OFF/vehicle OFF, disconnect the T2RR Antenna - Roof Rear coax cable at the T15 Navigation Antenna Signal Splitter.

2. Attach both leads of the EL-49903 - 1 OnStar test antenna to the EL-49903 - 5 combiner. Using the EL-49903 - 7 coax cable attach one grey connector to the combiner and the other grey connector to the T15 Navigation Antenna Signal Splitter. Place the test antenna on the roof of the vehicle, ignition ON.

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

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

1. Test the coax cable between the T15 Navigation Antenna Signal Splitter 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
2. Replace the T2RR Antenna - Roof Rear.

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

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

5. Attach both leads of the EL-49903 - 1 OnStar test antenna to the EL-49903 - 5 combiner. Using the EL-49903 - 6 coax cable attach the grey connector to the combiner and the brown connector to the K73 Telematics Communication Interface Control Module. Place the test antenna on the roof of the vehicle, ignition ON.

6. 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 the advisor can locate the vehicle.

7. Ignition OFF/vehicle OFF.

8. Test the coax cable between the T15 Navigation Antenna Signal Splitter and the K73 Telematics Communication Interface Control Module. 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.

9. Ignition OFF/vehicle OFF, disconnect the blue GPS coax cable connector at the K74 Human Machine Interface Control Module.

10. Attach the EL-49903 - 1 OnStar test antenna blue connector to the K74 Human Machine Interface Control Module and place the test antenna on the roof of the vehicle.

11. Ignition ON/vehicle in Service Mode.

12. Verify DTC B2462 is not set or that the NO GPS symbol/message is not displayed on the radio.

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

Replace the K74 Human Machine Interface Control Module

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

13. Ignition OFF/vehicle OFF.

14. Test the coax cable between the T15 Navigation Antenna Signal Splitter and the K74 Human Machine Interface Control Module. 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.

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.
• The vehicle may be equipped with sectioned coax. Test each section and replace only the faulty section, not the entire length of coax.

Coax Cable Test

1. Ignition OFF/vehicle 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 repair.

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

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