The paper describes the InBus-103 electronic equipment for the trolleybus traction system with vector controlled asynchronous motor. Based on the experience acquired during more years and hundreds of equipment installed and operational on urban vehicles from different cities, the equipment was developed using of the IGBT transistor technology, 32 bits Fujitsu micro-processors control systems, informational systems with optic fibers and CAN protocols. Due to the modular structure of the power electronics equipment and software implementation which has been developed within multifunction electronic control equipment, the whole system can be used both for trams and trolleybuses traction, using either AC or DC motors. It has also been developed a modern, user friendly graphic board panel which indicates all the functionality of the system. Laboratory tests were performed by using the facility of the company. They were followed by open field tests on a trolley prototype, also the property of the company. The trolley was loaded more than the rated value and the requirements higher than the specifications. All the tests have proven the good functionality of the equipment. According to the technical parameters, the exploitation facilities, the control algorithms and the performed functions, the InBus-103 proved to be a competitive product on the market of electric traction dedicated to the passenger urban units.