B2462

DTC B2462

Diagnostic Instructions

* Perform the Diagnostic System Check - Vehicle (Diagnostic System Check - Vehicle) prior to using this diagnostic procedure.
* Review Strategy Based Diagnosis (Strategy Based Diagnosis) for an overview of the diagnostic approach.
* Diagnostic Procedure Instructions (Diagnostic Procedure Instructions) provides an overview of each diagnostic category.

DTC Descriptors
DTC B2462 01
- Global Positioning System Short to Battery

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 thorough the center conductor of the antenna coax cable.

When the vehicle is equipped with the optional navigation radio, a navigation signal splitter is installed to distribute the navigation signal to both the telematics communication interface control module and the navigation radio. The telematics communication interface control module supplies 5 V through the coax cable to power the internal antenna amplifier through the signal splitter.

Conditions for Running the DTC

Onstar - Telematics Communication Interface Control Module
* Ignition is in the RUN or ACC position.
* System voltage is greater than 9 V and less than 16 V.
* The above conditions are present for greater than 1 second.

Navigation Radio
* Radio On.
* System voltage is greater than 9 V and less than 16 V.
* The navigation radio tests the GPS antenna every 10 seconds.

Conditions for Setting the DTC

B2462 01

The telematics communication interface control module and/or the navigation radio detect a short to B+ on the GPS antenna signal circuit.

B2462 02

The telematics communication interface control module and/or the navigation radio detect a short to ground on the GPS antenna signal circuit.

B2462 04

The telematics communication interface control module and/or the navigation radio detect an open/high resistance on the GPS antenna signal circuit.

Action Taken When the DTC Sets

Onstar - Telematics Communication Interface Control Module
* The OnStar(R) status LED turns red.
* The OnStar(R) Call Center cannot locate the vehicle.

Navigation Radio
* 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

* OnStar Schematics (OnStar Schematics)
* Radio/Navigation System Schematics (Radio/Navigation System Schematics)

Connector End View Reference

Component Connector End Views (Connector End Views By Name)
Description and Operation

* OnStar Description and Operation (OnStar)
* Radio/Audio System Description and Operation (Radio/Audio System)

Electrical Information Reference

* Circuit Testing (Circuit Testing)
* Connector Repairs (Connector Repairs)
* Testing for Intermittent Conditions and Poor Connections (Testing for Intermittent Conditions and Poor Connections)
* Wiring Repairs (Wiring Repairs)

Scan Tool Reference

Control Module References (Programming and Relearning) for scan tool information
Special Tools

EL-49903 GM 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 key on for the GPS satellites to acquire vehicle signal.

1. Ignition ON, wait 5 minutes, then contact the OnStar call center consultant by pressing the blue OnStar button. A call center consultant should answer the call, verifying the vehicle OnStar system is functioning and the consultant can locate the vehicle.

• If the OnStar system is not functioning and the vehicle is not equipped with a navigation radio, refer to Circuit System Testing Without Navigation Radio.
• If the OnStar system is not functioning and the vehicle is equipped with a navigation radio, refer to Circuit System Testing With Navigation Radio.

2. If equipped, verify the Navigation Radio functions while driving the vehicle.

• If the navigation radio does not function, refer to Circuit System Testing With Navigation Radio.

Circuit/System Testing

Without Navigation Radio
1. Ignition OFF, disconnect the coax cable connector at the K73 telematics communication interface control module.
2. Using the EL-49903-3 kit (EL-49903-5 adapter and EL-49903-4 coax cable), connect the EL-49903 to the K73 telematics communication interface module, place the test antenna on the roof of the vehicle.
3. Ignition ON, verify DTC B2462 is not set in the K73 telematics communication interface module.

• If DTC B2462 is set as current, replace the K73 telematics communication interface module.

4. Ignition OFF, disconnect the K73 telematics communication interface module coax at the T4G cellular phone, navigation, and digital radio antenna.
5. Perform the coax cable test on the coax cable, refer to Component Testing. The coax cable should pass the test.

• If the coax cable does not pass the test, replace the coax cable.

6. If all circuits test normal, replace the T4G cellular phone, navigation, and digital radio antenna.

With Navigation Radio
1. Ignition OFF, disconnect the coax cable connector at the K73 telematics communication interface control module.
2. Using the EL-49903-3 kit (EL-49903-5 adapter and EL-49903-4 coax cable), connect the EL-49903 to the K73 telematics communication interface module, place the test antenna on the roof of the vehicle.
3. Ignition ON, verify DTC B2462 is not set in the K73 telematics communication interface module.

• If DTC B2462 is set as current, replace the K73 telematics communication interface module.

4. Ignition OFF, disconnect the navigation antenna coax cable connector at the A11 radio.
5. Connect the EL-49903 to the A11 radio, place the test antenna on the roof of the vehicle.
6. Ignition ON, verify DTC B2462 is not set in the A11 radio.

• If DTC B2462 is set as current, replace the A11 radio.

7. Ignition OFF, reconnect the antenna coax cable connections at both the K73 telematics communication interface module and the A11 radio.
8. Disconnect the K73 telematics communication interface module coax at the T15 navigation signal splitter.
9. Ignition ON, 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.

10. Ignition OFF, disconnect the A11 radio navigation coax at the T15 navigation signal splitter.
11. Ignition ON, 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.

12. Disconnect the antenna coax cable from the T15 navigation signal splitter and the T4G cellular phone, navigation and digital radio antenna.
13. Perform the coax cable test on the coax cable between the T15 navigation signal splitter and the T4G cellular phone, navigation and digital radio antenna, refer to Component Testing. The coax cable should pass the test.

• If the coax cable does not pass the test, replace the coax cable.

14. Reconnect all coax cable connections at the T15 navigation signal splitter.
15. Ignition ON, test for 4.5-5.5 V between the coax cable center conductor and the outer shield at the T4G cellular phone, navigation and digital radio antenna.

• If not within the specified range, replace the T15 navigation signal splitter.

16. If all circuits test normal, replace the T4G cellular phone, navigation and digital radio antenna.

Component Testing

Caution: Refer to Test Probe Caution (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 ohm between both ends of the coax cables center terminals.

• If greater than the specified range, replace the coax cable

3. Test for less than 5 ohm between both ends of the coax cable outer shield.

• If greater than the specified range, replace the coax cable

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

• If less than the specified range, replace the coax cable.

Repair Instructions

Perform the Diagnostic Repair Verification (Verification Tests) after completing the diagnostic procedure.

* Navigation Signal Splitter Replacement (Service and Repair)
* Radio Antenna Base Replacement (Radio Antenna Base Replacement)
* Control Module References (Programming and Relearning) for telematics communication interface control module replacement, setup, and programming