Circuit/System Verification

NOTE:

For the GPS antenna to receive a clear signal, it is necessary that the antenna has an unobstructed line of sight to at least 3 satellites, which means the reception is best when there is open sky above the vehicle for at least 180°.

Ignition - On/Vehicle - In Service Mode
Verify the function: Exterior Lighting - ON - All Doors Lock/Unlock - Horn - ON
- If a condition exists
  Refer to: Diagnostic System Check - Vehicle
- Go to next step: If all functions work properly
Perform a test call with OnStar and verify the OnStar advisor can clearly hear you.
- If the component does not work as specified
  Refer to: Unable to Contact OnStar Call Center
- Go to next step: If the component works as specified
Verify the correct operation: OnStar - Command State = Exterior Lighting - ON - All Doors Lock/Unlock - Horn - ON
- If the component does not work as specified
  Replace the component: K73 Telematics Communication Interface Control Module
- Go to next step: If the component works as specified
All OK.