| • | Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure. | 
| • | Review Strategy Based Diagnosis for an overview of the diagnostic approach. | 
| • | Diagnostic Procedure Instructions provide an overview of each diagnostic category. | 
The Bluetooth ® antenna is a small fixed antenna connected directly to the communication interface module (CIM) and is used to send and receive signals from a Bluetooth ® enabled cellular phone. The antenna utilizes no cabling and is not external to the vehicle.
| • | Ignition ON. | 
| • | Battery voltage must be between 9-16 volts. | 
| • | The CIM tests the antenna once every second. | 
The CIM detects a short to ground or an open/high resistance in the Bluetooth ® antenna.
| • | The OnStar ® status LED turns red. | 
| • | Bluetooth ® functionality is disabled. | 
| • | The condition responsible for setting the DTC no longer exists. | 
| • | A history DTC will clear once 100 consecutive malfunction-free ignition cycles have occurred. | 
OnStar Description and Operation
Control Module References for scan tool information
| ⇒ | If the antenna is disconnected or damaged, repair or replace as necessary. | 
| ⇒ | If the DTC is set, replace the Bluetooth ® antenna. Clear the DTC and cycle the ignition OFF then back ON. If the DTC resets as current, replace the CIM. | 
Perform the Diagnostic Repair Verification after completing the diagnostic procedure.
| • | Control Module References for CIM replacement, setup, and programming |