B2462

DTC B2462 (Onstar/Navigation GPS Antenna)

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

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)
* Antenna Coaxial/Connector Cable Identification Table (Application and ID)

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 OnStar Malfunction without Navigation Radio.
• If the OnStar system is not functioning and the vehicle is equipped with a navigation radio, refer to OnStar Malfunction with Navigation Radio.

2. Verify the Navigation Radio functions while driving the vehicle.

• If the navigation radio does not function, refer to Navigation Radio Malfunction.

Circuit/System Testing

OnStar Malfunction without Navigation Radio
1. Ignition OFF, disconnect both the GPS and cell coax cable connectors at the K73 telematics communication interface control module.
2. Using the EL-49903-5 adapter with 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, wait 5 minutes, then contact the OnStar call center consultant by pressing the blue OnStar button. A call center consultant should answer the call, ask the consultant to verify the vehicle location to confirm the GPS system is functioning.

• If the OnStar GPS does not function, replace the K73 telematics communication interface module.

4. Ignition OFF, 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.

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

OnStar Malfunction with Navigation Radio
1. Ignition OFF, disconnect both the GPS and cell coax cable connector at the K73 telematics communication interface module.
2. Using the EL-49903-5 adapter with 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, wait 5 minutes, then contact the OnStar call center consultant by pressing the blue OnStar button. A call center consultant should answer the call, ask the consultant to verify the vehicle location to confirm the GPS system is functioning.

• If the OnStar GPS does not function, replace the K73 telematics communication interface module.

4. Ignition OFF, reconnect the coax cable to the K73 telematics communication interface module. Disconnect the coax cable from the T15 navigation signal splitter.
5. 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.

6. Ignition OFF, reconnect the coax cable to the T15 navigation signal splitter. Disconnect the coax cable from the T4G cellular phone, navigation and digital radio antenna.
7. Ignition ON, test for 4.5-5.5 V between the coax cable center conductor and the outer shield.

• If within the specified range, replace the T4G cellular phone, navigation and digital radio antenna.

8. Ignition OFF, 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.
• If the coax cable passes the test, replace the T15 navigation and signal splitter.

Navigation Radio Malfunction
1. Ignition OFF, disconnect the GPS coax cable connector at the navigation radio.
2. Using the EL-49903-5 adapter with EL-49903-4 coax cable, connect the EL-49903 to the navigation radio, place the test antenna on the roof of the vehicle.
3. Verify the navigation radio functions while driving the vehicle.

• If the navigation radio does not function, replace the navigation radio.

4. Ignition OFF, perform the coax cable test on the coax cable between the navigation radio and the T15 navigation signal splitter, refer to Component Testing. The coax cable should pass the test.

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

5. 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.

6. If all circuits test normal, replace the T15 navigation antenna signal splitter.

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 greater than 10k ohm 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 (Navigation Signal Splitter Replacement)
* Radio Antenna Base Replacement (Radio Antenna Base Replacement)
* Control Module References (Programming and Relearning) for telematics communication interface control module replacement, setup, and programming