Vehicle Diagnostics – The whole Story

1 20 years of automotive networking and diagnostics The fast growth of electronic functions in vehicles during the second half of the 1980s at first led to many insular solutions that prevented comprehensive concepts from taking hold in the area of electrical/electronic architectures. At the beginning of the 1990s a consolidation phase began that was marked by development of electrical/electronic structures and associated networking topology from a comprehensive perspective. This meant that electrical/electronic content and its networking could claim an undisputed position in the vehicle. The recognition that many functions could only be implemented sensibly with the help of electronics also prevailed. So the image of electronics transformed from being a necessary evil to being a key to new, interesting and innovative functions. The three bus nodes in commercial vehicles in 1989 have become more than 70 today in similarly equipped vehicles; see Figure 1. The underlying software amounts to about 10 million lines of programming code. This trend has not been without consequences for diagnostics either. Twenty years ago the diagnostic capability of a function was not even considered until shortly before production startup. Today basic diagnostic functions usually exist as early as in the B-Sample. Handling of diagnostics has improved significantly. In the times of flash codes the process required that users tediously count the number of flashes and convert them to error codes based on printed-out tables. Today testers output instructions in clear text. In the past it was possible to do without tool support entirely. Today powerful diagnostic tools are an everyday reality. It is possible to create the diagnostic specification, generate ECU-specific code and parameterize the diagnostic tester utilizing the “single source principle”. A precondition is that specification of diagnostics must be shifted to the beginning of the development process (Frontloading); see Figure 2. The ODX format also enables cross-OEM exchange of diagnostic data. The development and introduction of new diagnostic concepts and diagnostic solutions offer significant potential to automotive OEMs and suppliers for realizing efficiency gains and quality improvement. Growing complexity in automotive electronics can only be mastered – technically and economically – by use of nonproprietary standards such as ODX, close cooperation and powerful tools. This article offers an overview of topics relevant to the past, present and future of automotive diagnostics as presented and discussed in October 2006 before an audience of 350 participants at the Vector Congress in Stuttgart. Efficiency gains by standardization and the use of tool-supported processes in diagnostic development