Reliability in automotive electronics: a case study applied to diesel engine control

In this paper the problem of the reliability in automotive electronics, applied to the case of diesel engine control, in particularly to the Multijet ECU, is discussed. The aim of this paper is to define methodologies to estimate, to control and to improve reliability in automotive field. The functionality and the complexity of automotive electronic systems are rapidly growing and lead to increased networking, higher degrees of integration, and mechatronic solutions. Some electronic parts are placed under the hood or on the combustion engine or inside the gearbox, where environmental conditions are really harsh in terms of temperature, vibrations and shocks. Consequently, specific approaches in order to assure a high reliability level have been developed. In the first section of the paper the Multijet system is described, then a reliability analysis of the system using the reliability tool FMEA (Failure Modes and Effects Analysis) and FTA (Fault Tree Analysis) is presented. Eventually, the injector control subsystem is describes and its reliability analysis is presented. In the last part we try to find some links between the two different levels of abstraction in the reliability analysis.