This document describes a project to develop an automatic engine locking system for vehicles using a microcontroller to prevent drunken driving. It includes an alcohol detection sensor, AT89S52 microcontroller, power supply, buzzer, LCD display, motors, and other components. The system is intended to automatically detect if a driver has consumed alcohol and lock the engine if so. It aims to increase road safety by preventing accidents caused by drunken driving. Future enhancements could include GSM and GPS technologies to notify others of alcohol detection and track the vehicle's location.