The vehicle key is a safety device for the vehicle. Most keys on vehicles today still use physical keys, and some use keyless. This study examines the use of vehicle keys that are connected to smartphones. The method used in this research is literature study and experimental study. The technology used in this research is based on Arduino, and some of them are equipped with Bluetooth modules, HC-05, and relays. This solution is an initial study of the SmartKey system concept. This SmartKey provides a function to turn on and turn off the machine. The resulting SmartKey from the results of this research will make it easier for application developers to control critical functions and be equipped with remote turning on and off methods, and developing various other features through application development. The key generated in this study can be an alternative to lock system development in conventional motor vehicles.