Acceleration Slip Regulation (ASR) is an active car safety feature designed to reduce the engine speed and to slow down the wheels to ensure the most efficient acceleration.

The safety of cars on public roads has been, since the beginning of the industry, a permanent concern for manufacturers of cars and their accessories. The increasing speeds of these cars could cause very serious accidents, with even devastating consequences, so more and more efforts were made to achieve increased safety.

At first, engineers focused on introducing passive technologies in this regard, such as seat belts, but in recent years, active measures have become increasingly important, which are very much based on on electronics and which have turned public road travel into increasingly risk-free activities. These measures include the ASR system.

In the article below you will find out what ASR means, what its operating principles are and when it is recommended to stop it. You will also find a brief history of the implementation of this technology and some issues that may arise.

What is ASR car technology

The acronym ASR comes from the English language, from the expression Anti Slip Regulation. Specifically, this system deals with the regulation of traction, preventing the wheels from slipping at certain times, such as sudden acceleration when leaving the place or traveling on wet or slippery roads, such as those covered with snow, mud and ice.

What does ASR mean?

The role of the ASR system is to ensure the best possible grip of the tires on slippery roads by reducing the torque of the engine, when there is a slipping of a wheel. This can be done both by limiting the amount of fuel injected into the cylinders, by stopping the ignition in one or more cylinders, and by selectively applying the brake to the wheel that tends to slip.

By reducing the traction force, the tires make closer contact with the tread, and this will be noticed immediately by the stability of the vehicle and by reducing the amount of fuel consumed.

Today, the ASR system is found on most modern cars, being considered one of the essential technologies to ensure the stability of vehicles. Sometimes it is called TCS (Traction Control System) and performs the same role in the same way.

History of the implementation of ASR technology

In its current form, the ASR system is more common on cars and motorcycles in the 1990s, but attempts in this direction have been made since the 1930s, when Porsche invented a differential system, which allowed one of the wheels to it spins a little faster than the others, to improve traction. A modernization appeared only after another essential system for car safety was developed, namely, Anti-lock brake system (ABS). It has the role of stopping the complete locking of the wheels in case of braking.

A few years after the advent and implementation of the ABS system, engineers realized that they could use the system's sensors to implement a way to control traction. One of the first manufacturers to choose to introduce it was BMW, in 1979. In the following years, more and more people chose to use the system, making essential improvements, both in terms of reducing torque, by applying the brakes on each individual wheel. , as well as reducing engine power by limiting the amount of fuel injected.

Principles of operation of the ASR system

The ASR system has been designed to operate automatically, without the need for driver intervention in any way. Thus, it is good to know that it comes into action when starting the car and remains in use while driving, regardless of speed. There is a possibility of manual interruption, but it is recommended to do it only in special circumstances.

The system takes information from ABS sensors, which monitor the speed of the drive wheels. The on-board computer monitors and compares the acceleration and speed of all wheels. Thus, if it notices that one of the drive wheels is spinning faster than the others, it activates the traction control system which takes some measures:

• apply a braking force to the wheel in question;
• reduces the driving force by limiting the amount of fuel injected or by delaying the ignition of certain cylinders;
• use both ways to increase the vehicle's grip on the road;
• for vehicles with drive by wire acceleration, the computer may electronically limit the acceleration;
• in the case of vehicles with turbo engines, a solenoid can reduce the amount of air passing through the turbine and limit engine power.

Most of the time, when the system comes into action, drivers will not feel its intervention, because the changes are very fast, the sensors taking information several times per second and applying fine changes. Most cars, however, have an on-board indicator that will light up if the system works.

When it is recommended to turn off the car's ASR system

The ASR system is a safety one and should work all the time, even if it is possible to interrupt it with a simple push of a button. Many professional drivers complain that this technology affects performance, believing that their experience is sufficient to ensure the stability of the vehicle on the road.

This statement is not exactly true, especially in the case of high-performance cars, very powerful engines and sensitive accelerator pedals. In their case, especially when leaving the place, if the ASR is not connected, the wheels will skid in a vacuum, which will lead to three unwanted consequences:

• Increasing the amount of fuel consumed due to the spinning of the idle wheels, the engine power not being transmitted entirely to the road;
• Unnecessary tire wear due to intense friction with asphalt;
• Loss of control of the vehicle in extreme cases and unwanted incidents.

Switching off the ASR system is done manually, by briefly pressing the button, which will lead to a warning light, which will indicate that the ESP system is not working. For safety reasons, the ASR can be stopped in the case of cars with front-wheel drive, only at speeds below 50 km / h. Otherwise, the button cannot be used. On all-wheel drive vehicles, the ASR can be deactivated at any speed. After the reason for stopping the system disappears, the ASR will start by pressing the button again, which will also close the control panel.

Car safety experts recommend uninterrupted use of the system, especially since novice drivers who drive powerful cars would have problems if they choose to drive without its assistance. Regardless of the skill and skill of the drivers, they cannot overcome the electronic system that does thousands of calculations and interventions every second.

Proof of its performance is the fact that, when it intervenes, most drivers do not feel any change in the stability of the car, but only find that it is better on the road. There are some circumstances in which it is desirable to record a wheel slip that could not be recorded with the system running. In these circumstances, the ASR can be stopped at the touch of a button. The button is marked with the letters ASR, TSC, ESC or ESP, depending on the manufacturer.

These include the following situations:

If the car is driven on very slippery surfaces or in heavy snow, it is desirable that a certain slipping of the wheels occurs, in order to obtain a moment of movement. Otherwise, if the system is started and driven in such conditions, wheel slips will occur all the time, and the ASR system will automatically limit the engine power, which will make it very difficult to drive on such surfaces. Basically, a car with the ASR started in a very high snow will not be able to leave the place or will not be able to catch a satisfactory speed;
 
When driving with snow chains mounted on the drive wheels of the vehicle, it is good that the tires can skate a little, to ensure optimum grip on snow-covered surfaces;
 
The ASR system can be stopped in such a way that the maneuver to exit a slippery area, by swinging, is more efficient. So if a driver gets stuck with his car in a very slippery area, such as mud-filled pits or water-covered grass, and tries to use the swing to get out, the ASR system could limit his ability to escape. such situations, its stopping can mean the successful execution of the maneuver.
Car safety specialists come up with some interesting details that can help any driver in trouble. They recommend that, as soon as one emerges from such a situation presented above, the system be reconnected as soon as possible.

ASR system operating problems

The ASR system is designed to ensure traffic safety, so it must operate stably on the road. Thus, if the ABS does not work normally, the ASR system will not work when needed. Most cars have a warning light on board that will light up when the system is not operating at normal parameters.

Any driver can easily notice whether or not the ASR system has problems. Each time the engine is started, the computer automatically diagnoses the system. The on-board light will come on for a few seconds and turn off if everything is in order. If it stays on or flashes, then it is clear that the system has not passed the automatic diagnosis and that there are problems. The visit to the mechanic becomes mandatory for the car owner. Otherwise, traffic safety would be seriously endangered.

It is important that, when starting the car, drivers pay attention to which lights come on, how long they stay on, whether they go out or not, as they could indicate a problem.

Anyone wondering about the reasons that can lead to malfunctions of this system should find out some interesting information. The most common reasons for failure are not related to the owner's driving style or the proper maintenance of the car, but it seems that they occur due to the general wear of certain parts that make up its composition:

Speed ​​sensor failure. They transmit the number of wheel rotations, normally to the engine control unit. If the sensors do not work properly or not at all, the data will be incomplete or will not reach the computer of the system;
 
Steering angle sensor malfunctions. It is not directly part of the ASR system, being positioned on the steering column, but its failure could lead to the ignition of the ASR indicator on board and to the malfunction of the system;
 
Engine control unit software problems affect the functionality of the ASR system. In this case, a complete reprogramming or software update is required.