ESP: Everything you need to know

ESP System: What It Is and How It Works

The ESP (Electronic Stability Programme) helps ensure a car maintains its grip, even during sudden or unexpected movements. In this article, we explain what the ESP system is, how it works, and what can go wrong. We also look at how ESP works in conjunction with ABS.

What is ESP in a Car?

ESP, or Electronic Stability Programme, is a safety system designed to prevent a car from skidding during unexpected steering manoeuvres. It does this by reducing engine torque and/or selectively braking individual wheels. Since November 2014, all newly registered vehicles must be fitted with ESP.

The first ESP system was developed jointly by Mercedes-Benz and Bosch, and the term “ESP” is still used by many manufacturers. However, different car brands use various other abbreviations for similar systems:

• ESC (Electronic Stability Control): Škoda, Chevrolet, Hyundai, Lada, and Kia
• VDC (Vehicle Dynamic Control): Infiniti, Subaru, Alfa Romeo, Fiat, and Nissan
• VSA (Vehicle Stability Assist): Honda and Acura
• DSC (Dynamic Stability Control): Ford, Mazda, Land Rover, MINI, Aston Martin, BMW, and Jaguar
• DTSC (Dynamic Stability and Traction Control): Volvo
• MSP (Maserati Stability Programme): Maserati
• PSM (Porsche Stability Management): Porsche
  
  

How Does ESP Work?

The ESP system comprises sensors on the steering and suspension, a yaw rate sensor (which measures the car’s rotation around its vertical axis), a steering angle sensor, and the ESP control unit. The steering angle sensor monitors the intended direction of travel by comparing it to the direction the driver is steering.

The system checks up to 25 times per second for potential skidding. If a change in direction occurs, due to, for example, a sharp corner or an obstacle, the system intervenes with short braking actions. By braking individual wheels, ESP helps the car return to its intended path.

ESP works in tandem with the ABS, which prevents wheel lock-up during braking. When ESP activates, it is usually indicated by a flashing ESP warning light on the dashboard.

ESP Fault?

If the ESP light remains illuminated rather than flashing, this could point to a problem with vehicle stability. However, ESP warnings are not always caused by a fault in the ESP system itself. Issues such as incorrect tyre size, low brake fluid levels, or worn brake pads can also trigger a warning.

Common causes of actual ESP faults include:

• Defective microprocessor
• Faulty brake pedal position sensor
• Damaged ABS sensor wiring
• Faulty yaw rate sensor
• Malfunctioning onboard computer

The Benefits of ESP

ESP automatically corrects a vehicle’s course by adjusting braking or engine power, helping it stay on the intended path. Studies have shown that without ESP, up to 40% of fatal accidents are due to skidding. ESP can reduce the risk of skidding by as much as 80%.

According to research by the University of Cologne, mandatory ESP could prevent up to 4,000 deaths and 100,000 injuries each year.

ESP and ABS

ESP and ABS work together to enhance vehicle safety. While ABS prevents wheel lock-up during braking, maintaining grip and steering control, ESP provides extra stability by correcting a vehicle’s direction during unexpected manoeuvres or slippery conditions. If understeer or oversteer is detected, ESP can brake one or more wheels automatically.

Research shows ESP reduces single-vehicle accidents by up to 30%, which is why it has been a legal requirement for new cars since 2014.

ESP Through the Years

It may feel relatively new, but ESP—short for Electronic Stability Programme—was first introduced in passenger cars back in 1995. Since then, it has become a key safety feature, driven by technological advancements and legislative changes. ESP has grown in popularity and is now considered an essential component of modern vehicles.

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  1984: Bosch begins ESP development

  After Bosch began producing ABS systems in the 1970s, the idea of ​​further improving car safety arose a few years later. This idea came from Toyota, which equipped the Toyota Crown with "Anti Skid Control" in 1983. This improved form of ABS prompted Bosch engineers to take a closer look at the existing ABS and make it even more dynamic.
• 1992: Mercedes-Benz & Bosch partner

  The development of ESP suddenly gained momentum in 1992 when Mercedes-Benz and Bosch decided to collaborate. Mercedes-Benz is committed to equipping the latest S-Class with this revolutionary new stability system. The catch: This leaves only 36 months to make the system ready for production...
  
• 
  1995: Mercedes fitted the S-Class with ESP

  Bosch and Mercedes are keeping their word. Three years after the start of their partnership, the first Electronic Stability Program (ESP) goes into series production for the top model of the already exclusive S-Class: the S600. It took several years before ESP was available for this "affordable car," as the costs of manufacturing the ESP system were still so high at the time that it was only used in the most exclusive Mercedes models.
• 1997: The A-Class fails the "Moose Test"

  Two years after the launch of the S600, the ESP system was still too expensive for the cheaper models, but that changed quickly in 1997. Shortly after the launch of the new A-Class, this car failed the moose test: a well-known evasive manoeuvre that was regularly carried out by a Swedish car magazine at the time.
  
  The abrupt steering movement almost caused the car to fall onto its side! Mercedes then immediately went back to the drawing board. Several technical improvements were made, with the use of ESP being by far the biggest change. The test was then repeated, and voilà: the car continued driving smoothly on four wheels. This made the A-Class the first car from the "lower segment" to be equipped with ESP.
  Durch die abrupte Lenkbewegung wäre das Auto fast auf die Seite gefallen! Mercedes ging dann sofort wieder ans Zeichenbrett. Es wurden mehrere technische Verbesserungen vorgenommen, wobei der Einsatz von ESP die mit Abstand größte Änderung darstellte. Anschließend wurde der Test noch einmal durchgeführt und voilà: Das Auto fuhr auf vier Rädern sauber weiter. Damit war die A-Klasse das erste Auto aus dem „unteren Segment“, das mit ESP ausgestattet war.
  
  
  
• 
  1999: Mercedes fitted ESP as standard

  Following the success of the ESP equipment in the A-Class and the resulting safety gains, Mercedes has become the first car brand in the world to decide to install ESP as standard in every car.
• 
  2000: Data backs up the safety

  In 2000, Bosch published a study looking back on 5 years of ESP and concluded that ESP prevents 20–25% of car accidents involving loss of control.
• 
  2001: OEMs support the innovation

  Ford, Toyota, and Mercedes are conducting a joint study on the effectiveness of electronic stability systems, confirming the results of Bosch research. Even better: These three brands claim that 34% of potentially fatal accidents were prevented thanks to ESC/ESP!
• 2003: 10,000,000 ESP systems

  Eight years after launching the first ESP system, Bosch is launching its ten millionth ESP system. The success of the stability system's introduction in the A-Class and the results of various studies are driving continued market interest. More and more brands are recognising the need for a stability system.
  
• 2011: ESC/ESP becomes mandatory in Canada

  Canada is the first country in the world to require car manufacturers to equip new cars with an electronic stability system.
• 2012: ESC/ESP becomes mandatory in the USA

  Eight years after launching the first ESP system, Bosch is launching its ten millionth ESP system. The success of the stability system's introduction in the A-Class and the results of various studies are driving continued market interest. More and more brands are recognising the need for a stability system.

• 2013: ESP is fitted to a motorcycle

  Coincidence or not, but exactly 25 years after the introduction of the very first motorcycle ABS, the very first ABS for motorcycles with ESP functionality is being introduced. The KTM 1190 Adventure models are equipped with ABS/ESP from Bosch.
• 2014: 100,000,000 ESP systems

  With the introduction of stability systems in various countries, the number of cars with these features is increasing rapidly. While 10 million ESP systems were produced in the first eight years, this number increased by 90 million (!) in the following nine years, breaking the 100 million mark.
  
• 2014: ESC/ESP becomes mandatory in Europe

  Following Canada, the USA and Australia. Europe legislates that ESP must be fitted to all new models.
• 
  2017: 64% of new cars worldwide are fitted with ESP

  Increasede global legislation results in 64% of all new cars sold being fitted with ESP/ESC systems.
• 2020: 250,000,000 ESP Systems

  Twenty-five years after the introduction of the ESP system, Bosch announced that 250 ABS units with ESP functionality have now been produced. Furthermore, 15,000 lives have been saved in the EU thanks to ESP.
• 
  2020: 87% of all new cars sold worldwide are fitted with ESP

  According to Bosch 87% of all new cars sold worldwide are fitted with an ESP system.