Measurement of temperatures in engine and exhaust systems in automotive applications is necessary for thermal protection of the parts and optimizing of the combustion process. State-of-the-art temperature sensors are very limited in their response characteristic and installation space requirement. Miniaturized sensor concepts with a customizable geometry are needed. The basic idea of this novel sensor concept is to use thick-film technology on component surfaces. Different standardized and especially nonstandard material combinations of thermocouples have been produced for the validation of this technology concept. Application-oriented measurements took place in the exhaust system of a test vehicle and were compared to standard laboratory conditions.