The Brain in Your Car

By Shanuka Kadupitiyage | Published: 2:00 AM Jan 30 2021
Tech Talk The Brain in Your Car

By Shanuka Kadupitiyage

Cars have changed a lot over the past few decades. One of the biggest changes that have happened over the past few years is the continual increase of technology being used within our cars. Modern automobiles are now smarter than they have ever been, with facilities that we’ve only seen in science fiction before. Some cars feel more like a computer with wheels, rather than a regular automobile.

Besides the technology that we see and interact with, while seated in the cabin, our cars are now equipped with a range of amazing technological innovations, helping them to become faster and run more efficiently. As modern and cutting-edge as they may seem, the truth is that this is a work of technology that has been in the engines of our cars for decades.

We’re, of course, talking about what is popularly known as your car’s Engine Control Unit (ECU). Some people even call it an Engine Control Module (ECM), but we’ll stick to the more popular term for now.


Of course, you must be wondering why such a unit was ever introduced in the first place.

Before Electronic Fuel Injection (EFI) technology became popular, cars had what is called a carburetor to control the mixing of air and fuel to be used in the engine. Too much petrol in the mix would make the car’s engine run with a ‘rich’ air-fuel mix (which reduces fuel economy) while too little would make the engine run ‘lean’ and damage the engine. All of this was controlled mechanically, without any electronics. 

After using your car for a long period, or when you modify engine components (like adding a turbo kit) the original setup of your engine and carburetor changes. When that happens, a mechanic has to adjust the timing belt, see if the ignition of fuel is happening at the right time and make adjustments to the air-fuel mix.

Since, there were no electronics involved, they had to make little adjustments to the engine and the carburetor, and then listen to the engine if it was making the right sound. This whole process is called ‘tuning’.

After the world oil crisis in the 1970s, car manufacturers focused their attention on making their engines more fuel-efficient. Electronic fuel injection paired with an ECU was a major help in making that happen.

How it works?

Early cars with ECUs only measured oxygen and airflow to control the air-fuel mix accordingly. However, the ECU of a modern automobile does a lot more than that. Modern cars are equipped with a vast array of sensors that measure wheel speed, engine rpm, oxygen, airflow, temperature, and many more. The ECU takes this data and conducts a whole bunch of calculations to manage the air-fuel mix, ignition timing, valve timing, and engine rpm when idling and basically control how your whole car operates.

Your car’s ECU also registers if there is something wrong going on inside the car, and indicates that to the driver.

Why it’s important?

A modern-day automobile is completely dependent on its ECU operating correctly. Without it, our modern cars wouldn’t run as efficiently or as effectively as they do today. We wouldn’t be able to meet the modern standards of fuel efficiency in economy cars, nor would we be able to reach the heights of speed that modern sports-cars reach without them. 

As new technologies such as electronic steering, brakes, and acceleration are starting to become more commonplace, ECU technology and our dependence on it will only continue to increase. 

While I prefer the old-school, low-tech engineering found in classic cars because of how easily you can tweak and tinker with them, we must all accept that, cars that operate on an ECU run more efficiently and have better performance. This means that we all have to adapt to the times.

Tuning in the digital age

Earlier, we talked about how tuning with a carburetor worked in classic cars. However, because modern cars are mostly electronically managed, tuning a car that has an ECU requires not only mechanical expertise but also knowledge of software and programming. 

 While it made tuning and such a little more complicated (because you now need dedicated software to do it), it also unlocked a lot of potentials.

You may have seen ECU upgrade options in games like Need For Speed which enhance vehicle performance, but usually, you don’t need to because all these options for tweaking are usually preloaded into the system by the manufacturer nowadays.

By making tweaks to the ECU settings, you could easily enhance your vehicle’s performance throughout the rpm range, helping you get better, smoother power every time you step on the accelerator (something that couldn’t be done with a carbureted engine).

However, I doubt that most of us would ever modify our vehicles from what was initially set up by the manufacturer in the factory. Even if such modifications were made, we don’t have a proper track at our disposal to enjoy those changes in performance.

The biggest benefit that you and I could get from having an ECU is the ability to get engine diagnostics without even having to open up the engine bay.


Because electronics became heavily used in automobiles since the early ’90s, car manufacturers had to be able to get engine information in more sophisticated ways. Initially, each manufacturing company came up with their own way of getting diagnostic information when something is wrong with the car, which led to confusion among users and mechanics who enjoyed the simplicity of a carbureted engine before.

This is why a standard system interface was introduced and standardised throughout the world. Using an On-Board Diagnostics (OBD) tool, people could connect to the ECU of their car and get data on any errors detected by the many sensors available.

This technology has continued to become more sophisticated, and now we have the OBD II system. Modern OBD II ports and devices plug into a socket located in your driver cabin and not only let you identify errors or issues in your engine but also using a mobile app, you could even track real-time data from your car’s sensors about everything that’s going on in your engine.

Modern technology in automobiles has opened up completely new ways to enhance the performance in your car, with only minimal changes made. Would you be interested in using an OBD II device? Would you ever want to fiddle around with your car’s ECU? Let us know what you think of how modern cars have evolved with the times.

By Shanuka Kadupitiyage | Published: 2:00 AM Jan 30 2021

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