Micro-controller Based On-Board Diagnostic (OBD) System for Non-OBD Vehicles

This paper proposes the development of On-Board Diagnostic (OBD) system for automobiles. The proposed OBD system has a microcontroller based processing system and consists of (1) sensors installed at different parts of vehicle to observe various parameters, (2) processing unit that will take input from the sensors and signal conditioners, calculate the real-time values of vehicle parameters and give output and (3) user interface. System will be able to diagnose faults in parameters, abnormal abrupt changes, notify user of any abnormal condition, and in some cases indicate the cause of fault. This system is designed basically to be implemented on vehicles that do not have factory installed OBD systems, and can be easily fitted without major modifications to the vehicle. It is user friendly system with LCD and keypad interface though which user can view parameter values, warning notifications and define custom limits for different parameters according to vehicle (other than default values).