Determining the engine load reporting strategy of a vehicular on-board diagnostics system

摘要

An apparatus and method for discovering an engine load reporting strategy of an On-board Diagnostics (OBD) system in a vehicle with an engine, comprises examining OBD system data using an examining system. In particular, periods when the engine is idling are identified, preferably also using the OBD data. Engine idle periods may be identified by comparing the engine speed to an idling speed threshold. The idling speed threshold may be adjusted for engine running time, engine temperature, engine capacity and the fuel type of the engine. Periods when the vehicle is being held in a stationary state may be identified from a clutch checking means. A check may be made to ensure that the engine is running and a speed check may also be made to help determine periods of idling. A persistency check can be used and a latch circuit can store the result of the determination. The invention is used to determine whether a vehicleâ s OBD system is using the diesel-engine reporting strategy for engine load (based upon the percentage of maximum torque for a given engine speed) or whether the petrol-engine reporting strategy is being used (engine load reported as a percentage of maximum overall power).