Transport in human life has played a key role since ancient times. At the turn of years it has evolved, initially using only the power of human legs, then the animals until use internal combustion engines. The first internal combustion engine was presented by Brackenburow in 1836. The construction showed a very desirable type of combustion engine – burning a mixture of hydrogen and oxygen and expelling clean water as exhaust gas. However, the invention was abandoned due to its innovativeness and lack of trust in it. The topic was again taken in 1860 presenting a two-stroke engine using a mixture of natural gas and air with spark ignition. Striving for even greater perfection, Rudolf Diesel in 1893 presented and patented the first self-ignition diesel engine. The first solution, although used today, has shown that automotive engines leave a significant margin of reliability.
The operational reliability of internal combustion engines is important in relation to the conditions of their operation and technical condition. The impact of toxic substances in exhaust gases and their impact on the natural environment these days is an important issue.
One of the forms of work on the problem is the current diagnosis of engine operation. This was possible thanks to the use of the OBD I system, which was later transformed into OBD II / EOBD and the result of the test results obtained to the applicable EURO standards. The system allows testing during a road test in normal car operation. Using the OBD recorder, the operation of an example vehicle will be analysed in various operating conditions, and the obtained results will provide diagnostic possibilities.