This is installed next to the battery, or next to the fuse box, above or below the intake manifold. It is not difficult to find it in the engine compartment.

Dear, engine computer The board is under the main driver's seat. 1. ECU (Electronic Control Unit) electronic control unit, also known as "driving computer", "vehicle computer", etc. In terms of purpose, it is a special microcomputer controller for automobiles. It is the same as an ordinary computer, consisting of a microprocessor (CPU), memory (ROM, RAM), input/output interface (I/O), analog-to-digital converter (A/D), shaping, driver, etc. Made up of large scale integrated circuits.

To describe it in a simple sentence, "ECU is the brain of the car"