An electronic control unit for a working voltage not exceeding 1 000 V (so-called "Smart Key"), designed as a component of the electronic control system of a motor vehicle with dimensions of approximately 15 × 12 × 4 cm, comprising:
- a programmable memory controller with active and passive components, for example, transistors, diodes, a processor, resistors, capacitors and inductors,
- a built-in receiver for transponder communication (localization of the key) between the key and the unit.
The unit is connected to antennae already incorporated in the vehicle allowing the detection of the presence of the key near the vehicle.
The unit receives signals from manually operated buttons and from the antennae, processes them and on this basis controls devices, for example, locks or unlocks the vehicle doors, starts up the engine. It also controls the activation of signalling devices, for example, the control functions for key- free access including acoustic warning when the electronic key has left the vehicle.
[1][1]. https://eur-lex.europa.eu/legal-content/en/ALL/?uri=CELEX:32013R0704