The electronic stabilisation control (ESC) increases the car s stability. It reduces the tendency to skid and improves the stability and roadholding of the vehicle. The ESC detects critical handling situations, such as understeer, oversteer and wheelspin on the driven wheels. It stabilises the vehicle by braking individual wheels or by reducing the engine torque. The indicator lamp
in the instrument cluster starts flashing as soon as the ESC intervenes.
in the instrument cluster starts flashing as soon as the ESC intervenes.
The following systems are integrated in the ESC:
Anti-lock brake system (ABS)
ABS prevents the wheels from locking up under braking until the vehicle has reached a virtual standstill. You can continue to steer the vehicle even when the brakes are on full. Keep your foot on the brake pedal and do not pump the brakes. You will feel the brake pedal pulsate while the anti-lock brake system is working.
Brake assist system
The brake assist system can shorten the braking distance. The braking force is automatically boosted if you press the brake pedal quickly in an emergency. You must keep pressing the brake pedal until the danger has passed.
In the event of wheelspin, the traction control system reduces the engine torque to match the amount of grip available. This helps the car to start moving, accelerate or climb a gradient.
When the EDL detects wheelspin, it brakes the spinning wheel and directs the power to the other driven wheel (or wheels on quattro* versions). This function is not available at high speeds.
To prevent the disc brake of the braked wheel from overheating, the EDL cuts out automatically if subjected to excessive loads. The vehicle can still be driven. The EDL will switch on again automatically when the brake has cooled down.
Steering recommendation*
On vehicles with dynamic steering, the ESC can also adjust the steering angle to stabilise the vehicle in critical situations.
Selective wheel torque control
The selective wheel torque control function intervenes when cornering by braking the wheels on the inside of the bend individually as required. This enables precision cornering. The relevant system may not intervene in the wet or snow.
The “multicollision brake assist system” can help to reduce the risk of skidding and further collisions during an accident. If the airbag control unit detects that a collision has taken place upwards of a certain speed, the vehicle is braked by the ESC.
The vehicle will not be braked automatically if:
- the driver presses the accelerator,
- the brake pressure applied by pressing the brake pedal is higher than the brake pressure initiated by the system,
- or the ESC, the brake system or the vehicle s electrical system are not fully functional.
WARNING
- The grip provided by the ESC and the integrated systems is still subject to the physical limits of adhesion. Always bear this in mind, especially on wet or slippery roads. If you notice the systems cutting in, you should reduce your speed immediately to suit the road and traffic conditions. Do not let the extra safety provided tempt you into taking any risks when driving – this can cause accidents.
- Remember that the accident risk always increases if you drive fast, especially in corners or on a wet or slippery road, or if you follow too close behind the vehicle in front of you. Please bear in mind that even the ESC and the integrated systems cannot compensate for the increased accident risk.
- When accelerating on a uniformly slippery surface (for instance all four wheels on ice or snow), press the accelerator gradually and carefully. The driven wheels may otherwise start to spin (in spite of the integrated control systems), which would impair the car s stability and could lead to an accident.
Note
- The ABS and ASR systems can only work properly if all four tyres have a similar degree of wear. Any differences in the rolling radius of the tyres can cause the system to reduce engine power when this is not desired.
- The systems can make noises when they intervene.