An access control system includes an access control device, a wireless communication device, and a central controller. The central controller issues authorization codes to the wireless communication device. The wireless communication device is used by an authorized party to enable or activate a protected function secured by an access control device. To enable or activate the protected function, the authorized party uses the wireless communication device to transmit an access request to the access control device, which responds by transmitting an authentication challenge to the wireless communication device. The wireless communication device must transmit a valid authentication response based on the authentication challenge and a valid authorization code stored in its memory. If a valid authentication response is received, the access control device enables or activates the protected function.