Steer-By-Wire, Brake-By-Wire And Shift-By-Wire – How Do These Function?

In this edition of Automotive Technology content, we bring to you another interesting topic that is becoming increasingly popular these days. The aim of these articles under the automobile technology section is to try to explain the complex technical aspects of automobile engineering in a simple language. Many of our readers are automobile enthusiasts and are looking to get the information in a quick and easy-to-understand manner. That is the reason for choosing complex and modern technologies and give simple working principles and advantages and disadvantages of using that technology. This time around, we bring to you the importance of technologies like Drive-by-wire or Steer-by-wire and Shift-by-wire. What do these mean and what are the pros and cons of these technologies is what we are going to focus on in this post in detail. But before we move on, make sure to read all the latest developments in the world of the automobile industry on Car Blog India.

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Electronic Controls in Automobiles

Since the last few years, the dependence and usage of electronic components in a vehicle has multiplied severalfold. Almost every aspect of an automobile relies heavily on electronic control these days including electric-assisted powertrains, hybrid powertrains, interiors, features, safety and much more. Electronic communication has become the core aspect of automobile engineering these days and with the same advancement, we are moving in the direction of autonomous driving. That will be the epitome of technical advancement because all the aspects of the roads, safety and powertrain will be controlled by electronic components. This has already started to some extent with large-scale testing. This has been only possible due to the electronic components in the vehicle.

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The Engine Control Unit (ECU) has become the most integral part of any vehicle today, which is why it has earned the title of being the brain of the car. The level of computing power required in vehicles these days is far beyond human capabilities which is why the latest technologies are making use of the power of electronics to assist drivers in every possible way. This provides a lot of comfort and convenience to the drivers and is making our lives easier. Also, the safety aspects of the vehicles are controlled and enhanced by the use of electronics. This makes sure that the safety equipment in the car reacts before the human reflexes. This will remove any human errors that are very common in such scenarios. ECU monitors real-time data and situations through sensors and sends the necessary signals to the electronic components which are realized physically through the actuators. This is the general overview of how the ECU functions. The ECU already has a ton of data fed into it beforehand and covers all possible aspects.

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The very famous terms used these days are either steer or drive-by-wire. Essentially, both these terms signify the same thing. Currently, the steering column is connected to the wheels of a car through mechanical linkages and physical components. This has been the case for decades and a modern solution exists in the form of Steer-by-wire technology. In this, there are no mechanical linkages between the steering wheel and the wheels of the car. Instead, in fact, there are electrical connections like the cables and actuator and pump which are connected to the ECU of the car. A position sensor takes the driver’s input as to how much steering wheel has been turned by the drive and how much steering of the car is required. This is recorded and sent as a signal to the ECU of the car. The ECU processes this signal and sends out a command signal to the actuators which complete the necessary action needed to steer the car. This is how a steer-by-wire system works.

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Advantages and Disadvantages

There are a ton of advantages of having a steer-by-wire system installed in a car. This includes lesser mechanical components, lesser wear and tear, better maintenance ability, lesser weight, freedom to install the steering wheels anywhere inside the car, change the shape of the steering wheel to free up space for other essential and practical things and much more. There are not too many disadvantages of having this system apart from the initial cost. But this will come down drastically with the mass adoption of this technology in times to come.

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Brake-By-Wire / Drive-By-Wire

The overall principle of the brake-by-wire technology resembles the steer-by-wire technology but the specifics are a bit different. There is again, a position sensor attached to the brake pedal. The physical connection of the brake pedal with the brake assembly is removed and the brake pedal connects to sensors which, in turn, is connected to the ECU of the car. Here, the ECU again processes the signal and computes how much throttle has to be opened to fulfill the demand by the driver. Accordingly, it sends the signals to the actuator which performs the braking duties on the car. Similarly, the accelerator pedal inputs are also processed in the same way and the throttle valve is opened accordingly. This is what is called drive-by-wire. So, instead of controlling all these processes manually, a driver can simply give the input and the electronics of the car do all the work for you to remove the human intervention.

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There are plenty of automatic transmissions out there which use this technology. The recently launched Citroen C5 Aircross also comes with this technology called shift-by-wire. Here, there are electronics communicated between the driver’s input and the transmission system of the car. The gearshifts happen according to the throttle response of the driver. This enables smooth gearshifts because the signals that are generated are electrical and the actuators perform all the activities smoothly.


We hope you understood the concept of shift-by-wire, brake-by-wire and steer-by-wire through this post. The future of electronics in automobiles holds autonomous driving globally to make the roads a lot safer and eliminate any accidents due to human errors. It is also true that the machine can also falter and fail at times, but it is far less compared to human errors. Also, with evolving technology every day, the components and processes will become more sophisticated and advanced and the efficiency of these will be very high. To follow such interesting topics on automobile technology do visit this section on Car Blog India website.

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Image Source: Research Gate
