An engine control unit or brainbox, which is abbreviated as ECU is a processor that electrically collects data from sensors and uses the collected information to make changes to the engine component. The ECU is programmed to understand the working condition of the vehicle’s components. so, whenever there are changes in their working, the sensors notify the brainbox so that changes can be made. If a component is faulty, an error notification will be sent to the user, informing them a component has completely broken down.
An ECU is also said to be an embedded system in automotive electronics that controls one or more components or sub-systems in vehicles.
The system was introduced in the early 1980s, then it was used to control only fuel injections. This is why fuel is precisely injection into internal combustion engines. However, the improvement of electronics and engine design has spread the working function of the brain box or engine control unit to perform almost every operation in cars.
In some automotive where ECU is not widely used, precisely older ones, a Powertrain Control Module (PCM) is used as a control unit. It generally combines the controls of an Engine Control Unit (ECU) and a Transmission Control Unit (TCU).
The system determines when gear should be change, and it controls the system as it backs off the throttle to make the shift smoother. This PCM was introduced in the late 1970s but was highly recognized in the 1980s together with the electronic controlled carburetors and lockup torque converters.
Below are the applications of brainbox in a vehicle’s various components:
A brainbox is used in vehicles for controlling multiple functions such as cruise control, automatic gear shifting, climate control, engine running, fuel injection/ emission control, cooling system, ignition system, transmission system, charging system, collision avoidance, power mirror, seat & rear mirror controls, etc. in fact, almost all operation in modern vehicles is controlled by the brain box since its components are controlled electronically.
The PCM also senses and monitors various parts in the vehicle such as:
Ignition timing, by directing the speed of the firing spark plugs, making the vehicle’s engine to deliver an optimum amount of power per RPM.
It monitors the vehicle’s performance using sensors to check the temperature, oil and fluid level, air intake, emission level, camshaft angle, etc.
The PCM also helps to adjust the air-to-gas ratio that’s delivered into the vehicle’s combustion chamber, which results in fuel economy.
It ensures the vehicle's idle speed is not up to an unnecessary RPM.