A telematic control unit (TCU) in the automobile industry is the embedded system on board a vehicle that wirelessly connects the vehicle to cloud services or other vehicles via V2X standards over a cellular network. The TCU collects telemetry data from the vehicle, such as position, speed, engine data, connectivity quality, etc., from various sub-systems over data and control busses. It may also provide in-vehicle connectivity via Wifi and Bluetooth and implements the eCall function when applicable.

In the automotive domain, a TCU can also be a transmission control unit.

A TCU consists of:

• A satellite navigation (GNSS) unit, which keeps track of the latitude and longitude values of the vehicle
• An external interface for mobile communication (GSM, GPRS, Wi-Fi, WiMax, LTE or 5G), which provides the tracked values to a centralized geographical information system (GIS) database server
• An electronic processing unit
• A microcontroller, microprocessor, or field programmable gate array (FPGA) which processes the information and acts as an interface to the GPS
• A mobile communication unit
• Memory for saving GPS values in mobile-free zones or to intelligently store information about the vehicle's sensor data
• A battery module