In automotive electronics, an electronic control unit (ECU), also called a control unit, or control module, is an embedded system that controls one or more of the electrical systems or subsystems in a motor vehicle. Some modern cars have up to 80 ECUs, including:
- Engine Control Unit - also known as an ECU
- Transmission Control Unit - TCU
- the above two may be combined, and referred to as a Powertrain Control Module (PCM)
- Airbag control unit - ACU
- Telephone Control Unit - TCU dials telephones for you and talk to your friends
- Man Machine Interface - MMI
- Body Control Module - controls door locks, electric windows, courtesy lights etc.
- Door Control unit
- Seat Control Unit
- Climate Control Unit
- speed control unit
- Convenience control unit - CCU
Managing the increasing complexity of ECUs and number of ECUs in a vehicle has become a key challenge for original equipment manufacturers (OEMs).
In some older vehicles, the ECU is referred to as an ECM (electronic control module).