OnStar Button LED Malfunction (with DRC or DRG)

OnStar Button LED Malfunction (with DRC or DRG)

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.

Circuit Description

The OnStar(R) status LEDs are located in the inside rearview mirror. The green LED is illuminated when the system is ON and operating normally. When the green LED is green and flashing, it is an indication that a call is in progress. When the red LED is illuminated, a system malfunction is present. In the event there is a system malfunction and the OnStar(R) system is still able to make a call, the LED will flash red during the call. The OnStar(R) LEDs are controlled internally by the A10 inside rearview mirror via serial data from the telematics communication interface control module from the Low Speed GMLAN Bus.

Reference Information

Schematic Reference

OnStar Schematics OnStar Schematics

Connector End View Reference

Component Connector End Views A/C Compressor Clutch

Description and Operation

OnStar Description and Operation OnStar

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 Control Module References for scan tool information

Circuit/System Verification

Note: If the green LED is off with the ignition ON and the LED functions correctly when commanded with the scan tool, contact the OnStar Center to confirm the vehicle has a current subscription. When rear camera display is in the Inside Rearview Mirror the LED's are non-serviceable because they are internal to the mirror.

1. Ignition ON.

2. Verify no U-code is set.

• If a U-code Is Set
Refer to Control Module U Code List Control Module U Code List

• If a U-code Is Not Set

3. Verify DTC B2476 or B2482 is not set.

• If DTC B2476 or B2482 is set
Refer to DTC B2476 or B2482 B2476

• If DTC B2476 or B2482 is not set

4. Verify that the green LED turns ON and OFF when commanding the green indicator ON and OFF with a scan tool.

• If the green LED does not turn ON and OFF
Replace the A10 Inside Review Mirror.

• If the green LED turns ON and OFF

5. Verify that the red LED turns ON and OFF when commanding the red indicator ON and OFF with a scan tool.

• If the red LED does not turn ON and OFF
Replace the A10 Inside Review Mirror.

• If the red LED turns ON and OFF

6. All OK.

Repair Instructions

Perform the Diagnostic Repair Verification Verification Tests after completing the repair.

* Inside Rearview Mirror Replacement Inside Rearview Mirror Replacement

* Control Module References Control Module References for telematics communication interface control module replacement, programming and setup.