Yes, you can completely disable OnStar if it is installed in your vehicle. Here are the steps to do so:
• Locate the OnStar fuse in the fuse box of your car.
• Disconnect or remove this fuse from its slot.
• The OnStar service will be disabled once this process is complete.
• You may also need to contact a qualified technician to ensure that all components related to OnStar have been disconnected and removed from the vehicle.