The Development of a New Automotive Diagnostic Approach

This thesis describes the master by research project “The Development of A New Automotive Diagnostic Approach” and contains the current diagnostic approach, the own developed idea of a new diagnostic method and the hardware design of a new diagnostic tool for vehicles.

The messages of the sensors and control units are transmitted over the in-vehicle bus network and are different depending on the condition of the car. The new diagnostic approach uses our developed theory, that the bus level changes between faultless and faulty vehicle condition.

The thesis enables an understanding of the basic principles of automotive electrics, control
systems and the subjacent fault diagnostic principles. To understand these complex diagnostic principles, the different protocols and standards are described.

A hardware interface to the in-vehicle bus system is shown which can be used for many different applications, like manipulating/monitoring existing CAN networks, as a diagnostic tool, creating own control systems or for automotive security experiments. The main components of the hardware are an Atmel AT90CAN128, the Philips CAN
transceiver PCA82C251, the FTDI FT245BM USB FIFO and the VNC1L USB host controller. The interface developed in this project gets the same results as an up to date conference paper published for for IEEE.

Based on the shown in-vehicle bus interface in this thesis an idea of a new control system for cars is described. The idea is to control the tyre pressure during an automatic vehicle emergency break. The idea is a reduction of the collision speed and therefore a further reduction of the stress for the vehicle passengers and the resulting injuries for vehicle occupants.