What is ESC (electronic stability control)?

  • Parkers guide to the safety feature, ESC
  • How electronic stability control works and when to engage it
  • Also known as ESP (electronic stability programme)

In the car, you may have noticed the ‘ESC’, or electronic stability control, button by your handbrake or down near your knee and wondered what it does. It’s usually engaged by default, and you have to select the button to disengage it. But what exactly does it do? And when is the appropriate time to disengage ESC?

Since it’s referred to more recently as dynamic stability control (DSC) and electronic stability programming (ESP), if you feel you’re eating acronym soup, you’re not alone. Parkers explains more…

What is ESC?

ESC, or electronic stability control, is a driver assistance safety feature. The car’s on-board computer uses a collection of sensors to react to a loss in grip of the wheels on the road, known as traction.

A loss in traction, coupled with bodyroll, can cause the car to spin or flip, if enough speed is applied, i.e. taking a corner too quickly. As the number of electronic controls has increased in vehicles, engineers have been able to use them to mitigate against unnecessary accidents.

Though ESC helps avoid a vehicle skidding out-of-control, it’s still possible, even with the feature engaged, to have an accident. Slippery surfaces, such as oil on the road, can also cause the wheels to slide, triggering this safety feature.

How does ESC electronic stability control work?

ESC sensors are fitted to each of a vehicle’s wheels. Measuring the rotational speed of each individual wheel, the data is fed back to the on-board computer at lightning speed. The sensors check to see whether the car is behaving in manner consistent with regular driving.

If they detect that it is not – in reaction to a loss of grip at the wheels or the direction the vehicle is travelling versus the amount of steering lock applied – they act to correct this.

These corrections can take the form of reducing engine power, braking individual wheels and can, provided other safety systems are fitted control the steering.

The system enables the driver to regain control and prevent a skid, or worse still, a spin.

Do I need ESC?

Yes. Since the mid-1990s, ESC has been present in cars. In 2014 though, the UK mandated that every new vehicle had to be build with ESC, since it’s so effective. As cars fitted with electronic stability systems are less at risk of an accident, insurance is cheaper, too. Every car with ESC has an anti-lock braking system (ABS) and a traction control system (TCS), AKA traction control, as the sensors and hardware are very similar. This whole safety suite helps you to stay safe on the roads.

Such driver assistance systems (DAS) have now been coupled with additional features such as blind-spot detection, parking sensors, rear parking cameras and radar-based pedestrian detection, known as advanced driver assistance systems (ADAS), which are also being integrated into insurance policy calculations. Though this stuff might sound a bit too techy and complicated, it’s worth considering, not least for the safety, but also the cost-savings of running your vehicle. 

When is it ok to disengage ESC?

Unless you’ve been professionally trained in advanced motoring, and even if you have, it’s rarely a good idea to disengage ESC. It’s there to avoid a (potentially fatal) accident. But there are a couple of times you may need to disengage it; selecting the ESC button and holding it for about five seconds will initiate ‘OFF’. Then you’ll see a dashboard light on the cluster display to confirm the action.

1. If you’re on a race track

If you’ve got a bit of a pleasure-seeking ‘need for speed’ and you’re taking your own—appropriately insured—vehicle out on a race-track, then ESC imay be working against you.

We wouldn’t advocate losing the ESC until you’re suitably competent on the track and, frankly, if you don’t know when that time has come, you’re not ready to turn it off yet. (Remember, you have to drive yourself home, so it isn’t a great idea to total the car.)

Learning to handle your vehicle properly is a skill that transfers well to driving on public roads, but ESC should ideally remain engaged on them.

2. In snowy conditions from parked

Very slippery surfaces, such as muddy off-roading or snow conditions, can confuse ESC sensors to the extent that they completely prevent the vehicle from moving. Sometimes turning the system off is the only way to get the wheels to rotate enough to get you moving.

Be cautious, though, as without the ESC on you’ll also be a greater risk of sliding or skidding once you’re on the move, so best turn it back on as soon as you can. Again, this is only a last resort, as ESC can cope with most road conditions. What’s more, some modern cars have multiple drive modes, enabling you to toggle the engine mapping specifically for such conditions.

What if ESC fails?

If you get a warning light on your dash, suggesting a problem with the ESC, you can still drive the vehicle. However, it is worth consulting your garage or dealership workshop to ascertain what the problem is—most likely a faulted sensor.

Looking for more jargon-busting motoring meanings? Head over to our Parkers Car Glossary page and take a look at our other definitions