Circuit/System Verification

NOTE:

It is necessary to inform the OnStar® Call Center advisor that this call is for vehicle diagnostic purposes.
It is necessary to have the vehicle in an open outside area where a cellular call can be successfully placed and GPS data can be received from satellites.

Ignition ON/vehicle in Service Mode.
Verify that the horn, lights and the door locks on the vehicle operate properly.
- If an applicable vehicle system does not operate properly
  Refer to Diagnostic System Check - Vehicle .
- If all applicable vehicle systems operate properly
Verify that a call can be successfully placed to the OnStar® Call Center by pressing the blue OnStar® button.
- If unable to contact the OnStar® call center
  Refer to Unable to Contact OnStar Call Center
- If able to contact the OnStar® Call Center
Verify with the OnStar® advisor that all remote functions (door locks, lights and horn) work.
- If the remote functions do not operate when requested
  Replace the K73 Telematics Communication Interface Control Module
- If the remote functions operate when requested
All OK.