Vehicle E/E architecture is the way a car's electrical and electronic parts are arranged: the wiring, the connectors and the small computers that control each system. E/E stands for electrical and electronic. It decides which computer controls which part of the car, and how they exchange data with each other.
A modern car has dozens of small computers, each an electronic control unit (ECU). In the old design, each system had its own computer. One ran the windows, another the airbags, another the motor. The wiring between them could run to several kilometres in a car, and weigh tens of kilograms. The computers were joined by slow shared networks, such as the CAN bus, on which each one sends short messages.
Carmakers are now merging these computers into fewer and more powerful ones. Each powerful computer runs many systems, and a faster network joins them. There are two reasons. Fewer computers and shorter wires reduce cost and weight. More important, software can then run more of the car, and one update can change many systems. This is the base of a software-defined vehicle.
Consider a carmaker redesigning its mid-size SUV. In the old design, 80 ECUs sit in different parts of the car, each with its own wires. In the new design, 5 powerful computers each control one area of the car, such as the front or the dashboard. The 5 computers are joined by a fast network. The wiring is shorter, and a single over-the-air update can reach every system through them.
This is a hard change. A carmaker has to move software that was written for 80 separate computers onto 5. Each system must still act at the right instant, so the work needs a real-time operating system. The carmaker usually decides the design. A Tier 1 supplier then builds the computers and the wiring.
The architecture connects everything else. It carries the readings of cameras, radar and lidar, runs the digital cockpit, and passes commands to the powertrain and to safety electronics. It is built from connectors and cable assemblies and is designed with model-based design.