document_0900452a81b1b9de.book Seite 222 Donnerstag, 26. Juli 2007 9:16 09
222
Intelligent technology
Intelligent technology
Electronic differential lock (EDL)
Electronic stabilisation program (ESP)
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 active up to about 100 km/h.
Description
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 automati-
cally when the brake has cooled down.
ESP increases the car's stability. It reduces the tendency to skid and
improves the stability and roadholding of the vehicle. ESP 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 warning
lamp in the instrument cluster starts flashing as soon as the ESP
intervenes.
Dynamic steering*
On vehicles with dynamic steering*, the ESP can also intervene in
the steering to stabilise the vehicle in critical situations.
The ESP incorporates the functions of the anti-lock brake system
(ABS), the traction control system (ASR), the electronic differential
lock (EDL) and the dynamic steering*.
WARNING
• The grip provided by the ESP, ABS, ASR, EDL and dynamic
steering* 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.
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
• Please remember that the accident risk always increases if you
drive fast, especially in corners or on a slippery road, or if you
follow too close behind the vehicle in front of you. Please bear in
mind that even ESP, ABS, brake assist, EDL, ASR and dynamic
steering* cannot compensate for the increased accident risk.
The brake assist system can speed up the braking process and
shorten the braking distance. It automatically boosts the braking
force if you press the brake pedal quickly in an emergency. On vehi-
cles with adaptive cruise control*, the brake assist system will build
up a small amount of pressure in the hydraulic brake system if it
senses that you are too close to the vehicle in front.
• 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.
Traction control system (ASR)
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.
English 
