Development of a CAN Bus-Based Vehicle Health Monitoring System for Commercial Transport in Delta State

Commercial transport operators in Delta State, South South Nigeria, experience high vehicle breakdown rates attributable to deferred maintenance and the absence of real-time engine health monitoring in their ageing fleets. This project developed a Controller Area Network bus-based vehicle health monitoring system that reads standard OBD-II diagnostic parameters from a vehicle's ECU and wirelessly transmits health data to a fleet manager's smartphone application. An ELM327 OBD-II Bluetooth adapter was interfaced with an ESP32 microcontroller to parse CAN bus data including engine RPM, coolant temperature, fuel level, battery voltage, throttle position, and diagnostic trouble codes. The parsed data were transmitted via Bluetooth to an Android app that displayed real-time gauges, stored historical trip data in a local SQLite database, and generated maintenance alerts when parameters exceeded safe thresholds. The system was validated on three commercial buses (Toyota Coaster, Hiace H300, and Mercedes Sprinter) operating on the Asaba to Warri route. All 14 tested OBD-II parameter IDs were successfully read and decoded. Alert accuracy for over-temperature and low-fuel conditions was 100 percent in controlled testing. Bluetooth communication range was 8.4 metres. Trip data logging interval was one second with no observed data loss over 4-hour test drives. The study recommends extending the platform with a 4G data uplink for real-time cloud fleet management dashboards, and adding GPS tracking for route and idle-time analytics relevant to Delta State transport operators.

Keywords: CAN bus, OBD-II, vehicle health monitoring, fleet management, Delta State