Electronic stability control

Electronic stability control (ESC) helps you remain in control of your vehicle when you skid, swerve suddenly or when road conditions change.

When new vehicles are first registered in Victoria, they must be fitted with electronic stability control (ESC). This requirement applies to all passenger cars, off-road passenger vehicles, and forward-control passenger vehicles (e.g. passenger vans) with a compliance/identification plate date of 01/11 or after.

Also known as electronic stability programs (ESP), ESC builds upon features such as anti-lock braking systems (ABS) and traction control to stabilise the vehicle when it changes direction from that intended by the driver.

Why ESC?

European experts estimate that up to 40% of single vehicle crashes could be avoided if all cars had ESC. In Victoria that means 50 lives a year could be saved.

ESC considerably reduces the risk of single vehicle crashes by:

  • correcting impending oversteering or understeering
  • stabilising the vehicle during sudden evasive manoeuvres e.g. swerving
  • improving handling on gravel and unmade roads e.g. road shoulders, and
  • improving traction on slippery or icy roads.

Australian research indicates that ESC is effective in reducing single vehicle crashes by 29%.

How does ESC work?

Using a number of intelligent sensors, ESC immediately identifies when a car has deviated from the driver’s steered direction and the driver has lost control of the vehicle. As soon as impending instability, oversteering and understeering are registered, ESC stabilises the vehicle by selectively braking individual wheels and reducing engine torque to bring the vehicle back on course.

Electronic stability control diagram showing the effects of oversteering

  • Oversteer – the vehicle’s rear tries to break away towards the outside of the curve.
  • ESP then brakes the outside front wheel (red) to reduce the danger of skidding.

Electronic stability control diagram showing the effects of understeering

  • Understeer – the vehicle’s front tries to break away towards the outside of the curve.
  • ESP then brakes the inside rear wheel (red) to reduce the danger of skidding.

How is ESC different to ABS and traction control?

ESC uses components of anti-lock braking systems (ABS) and traction control to stabilise the vehicle. Unlike ABS and traction control which only operate in the driving direction (longitudinal), ESC also helps the driver control sideways (lateral) movements which create instability. This makes ESC a total, holistic system that controls a car’s entire movements.

Do I need training to drive a vehicle with ESC?

No. System manufacturers say that ESC supports the driver but does not require training or changes to driving styles.

Does ESC take over control from the driver?

No. But it assists the driver to maintain control of the vehicle.

To comply with regulations, manufacturers will need to fit a “compliant system of ESC” to their vehicles.

According to the Road Safety (Vehicles) Regulations 2009 a compliant system of ESC refers to a system that:

  1. complies with the United Nations electronic stability control standard (External link), or
  2. has been determined to be acceptably equivalent to that standard by VicRoads.

For the purpose of the Road Safety (Vehicles) Regulations 2009, to have an acceptably equivalent Electronic Stability Control (ESC) system a vehicle will have all of the following attributes.

  • That improves vehicle directional stability by at least having the ability to automatically control individually the braking torques of the left and right wheels on each axle (An axle group shall be treated as a single axle and dual wheels shall be treated as a single wheel.) to induce a correcting yaw moment based on the evaluation of actual vehicle behaviour in comparison with a determination of vehicle behaviour demanded by the driver.
  • That is computer controlled with the computer using a closed-loop algorithm to limit vehicle oversteer and to limit vehicle understeer based on the evaluation of actual vehicle behaviour in comparison with a determination of vehicle behaviour demanded by the driver.
  • That has a means to determine directly the value of the vehicle's yaw rate and to estimate its side-slip or side-slip derivative with respect to time.
  • That has a means to monitor driver steering inputs.
  • That has an algorithm to determine the need, and a means to modify propulsion torque, as necessary, to assist the driver in maintaining control of the vehicle.
  • Is operational over the full speed range of the vehicle at or above at least 20 km/h, during all phases of driving including acceleration, coasting, and deceleration (including braking), except:
    • When the driver has disabled ESC*, or
    • While the initial start-up self test and plausibility checks are completed, or
    • When the vehicle is being driven in reverse, or
    • For attributes/operations that are excluded in gtr 8
  • Remains capable of activation even if the antilock braking system or traction control system is also activated.
  • The vehicle shall be equipped with a tell-tale that provides a warning to the driver of the occurrence of an ESC malfunction.

* ESC Systems that can be switched off are permitted provided that:

  1. a visual indicator is provided which activates whenever the ESC system is switched off, and
  2. the ESC system is activated automatically each time the ignition is switched on.

Vehicles manufactured on or after 1 January 2011 (i.e. compliance plate is after 1 January 2011) are required to have a compliant system of Electronic Stability Control (ESC).

This ESC requirement applies to the following.

  • Passenger cars - a passenger vehicle having up to nine seating positions, including the driver. This does not include an off-road passenger vehicle or a forward-control passenger vehicle.
  • Forward-control passenger vehicles - a passenger vehicle having up to nine seating positions, including the driver, and in which the centre of the steering wheel is in the forward quarter of the vehicle’s total length. This does not include off road passenger vehicles.
  • Off-road passenger vehicles - a passenger vehicle having up to nine seating positions, including the driver and being designed with special features for off-road operation.

This ESC requirement does not apply to:

  • a motor vehicle that has been registered in another state or a territory of the Commonwealth for one year or more immediately before the motor vehicle is brought into Victoria
  • a motor vehicle that is not manufactured or marketed in full volume for normal road use
  • a vehicle registered as a Specialist and Enthusiast Vehicle
  • a model of motor vehicle that has been declared by VicRoads to be exempt.

For more details, refer to the Road Safety (Vehicles) Regulations 2009 [PDF 2.8 Mb]

VicRoads has published a list of vehicles that comply with, or are exempt from the requirement to have a compliant ESC system. This list applies only to those makes and models with a compliance plate of January 2011 or after. Please note that more models will be added to the table once certification applications have been processed.

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