Deutsche Version
English version



The word „diagnosis“ has its origins in the Greek language and means:

differentiating assessments or insight based on precise observations and investigations.

In the sector of car electronics, a diagnostician needs comprehensive knowledge in different scientific fields. Some samples are listed below:


Required knowledge


smelling air conditioner

chemistry, physics

no clearance for starting

electromagnetic waves, digital technology, opto-electronics (electrophysics, computer sciences)

bucking motor when accelerating

mechanics, hydraulics, electrostatics, magnetostatics, digital technology, (electrophysics, organic chemistry, thermodynamics, computer sciences)




Vehicle diagnostics systems are applications which are used during the complete life span of control devices in vehicles. The life span encloses the development and the production as well as the service of the control devices in service centers.

Here, car diagnostics systems use on-board-functionalities of the several ECUs. In connection with the evaluation of the several data bus communication it allows a detailed fault analysis.

Term and definition
A vehicle diagnostics system is an analysis tool consisting of hard- and software which generally allows the reading out of the control device data and the recording of the data bus communication (tracing).

These systems are applied during test drives and in service centers for a quick error detection and analysis. For a final evaluation the data bus communcation (CAN, LIN, MOST, Flexray, K-line) are related with the error memory.

The early error detection, analysis and rectification is a vital factor of success in the development of new vehicle generations. Decreasing development periods and increasing complexity are complicating the guarantee of a high quality standard in the start of industrial production. The rising number of new functions which are realized by several control devices causes a complex network among the software of the several control units.

Furthermore, dynamic interdependences (for example processing orders or time conditions) of the several control units together with unsufficiently realistic simulation of sensors and actuators cause errors which can be detected by vehicle diagnosis systems and analysis tools during test drives.

back to top