slush or snow, ESC cannot perform the same way it would on a dry surface. If the vehicle “hydroplanes” (rides on a cushion of water instead of the road surface), ESC will not be able to help you steer the vehicle because contact with the pavement has been interrupted and the vehicle cannot be braked or steered. During fast cornering, particularly on winding roads, ESC cannot always deal as effectively with difficult driving situations as it can at lower speeds.
Always adjust your speed and driving style to visibility, road, traffic, and weather conditions. ESC cannot override the vehicle's physical limits, increase the available traction, or keep a vehicle on the road if road departure is a result of driver inattention. Instead, ESC improves the possibility of keeping the vehicle under control and on the road during extreme maneuvers by using the driver's steering inputs to help keep the vehicle going in the intended direction. If you are traveling at a speed that causes you to run off the road before ESC can provide any assistance, you may not experience the benefits of ESC.
ESC includes and/or works together with the ABS, BAS, ASR, EDL, and XDL systems (see below). ESC is switched on all the time. In certain situations when you need less traction or additional traction
cannot be achieved, you can switch off ASR by pressing the mbutton ⇒ fig. 133. Be sure to switch ASR on again when you no longer need less traction.
Anti-Lock Brake System (ABS)
ABS helps to keep the wheels from locking up and helps to maintain the driver's ability to steer and control the vehicle. This means the vehicle is less likely to skid, even during hard braking:
x Push the brake pedal down hard and hold it there. Don't take your foot off the pedal or reduce the force on the pedal!
x Do not “pump” the brake pedal or let up on it!
x Steer the vehicle while pushing down hard on the brake pedal.
x ABS stops working if you release or let up on the brake.
When ABS is doing its job, you will notice a slight vibration through the brake pedal and hear a noise. ABS cannot shorten the stopping distance under all conditions. The stopping distance may even be longer, for instance, when driving on gravel or on newly fallen snow covering an icy or slippery surface.
Brake Assist (BAS)
The Brake Assist System can help to reduce stopping distances. If you press the brake pedal very quickly, BAS detects an emergency situation. It then very quickly builds up full brake system pressure, maximizing braking power and reducing the stopping distance. This way, ABS can be activated more quickly and efficiently.
Do not reduce pressure on the brake pedal! BAS switches off automatically as soon as you release or let up on the brake.
Anti-Slip Regulation (ASR)
ASR reduces engine power directed to spinning wheels and adjusts power to the road conditions. Even under poor road conditions, ASR can make it easier to get moving, accelerate, and climb hills.
ASR can be switched on or off manually ⇒ page 308, Switching Anti-Slip Regulation (ASR) on and off.
Electronic Differential Lock (EDL and XDL)
EDL is applied during regular straight-line acceleration. EDL gently brakes a drive wheel that has lost traction (spinning) and redirects the drive force to other drive wheels. In extreme cases, EDL automatically switches off to keep the brake from overheating. As soon as the brake has cooled down, EDL automatically switches on again.
XDL is an extension of the Electronic Differential Lock system. XDL does not react to drive wheel slippage when driving straight ahead. Instead, XDL detects slippage of the inside front wheel during fast cornering. XDL applies enough brake pressure to this wheel in order to stop the slippage. This improves traction, which helps the vehicle stay on track.
WARNING
Driving fast on icy, slippery, or wet roads can lead to a loss of control and result in serious personal injury for you and your passengers.
x Always adjust your speed and driving style to road, traffic, weather, and visibility conditions. Never let the additional safety that ESC, ABS, BAS, ASR, and EDL can provide tempt you into taking extra risks.
x Braking assistance systems cannot overcome the laws of physics and always prevent loss of vehicle control. Slippery and wet roads are still dangerous even with ESC and the other systems!
x Driving too fast on wet roads can cause the wheels to lose contact with the road and “hydroplane.” A vehicle that has lost road contact cannot be braked, steered, or controlled.
x These systems cannot reduce the risk of accident, for example if you drive too fast for conditions or if you do not keep your distance from the vehicle in front of you.
x Although these systems are very effective and can help you control the vehicle in many difficult situations, always remember that your vehicle handling control is limited by tire traction.
x When accelerating on a slippery surface, for example on ice and snow, depress the accelerator carefully. Even with these systems, the wheels may start to spin, leading to a loss of vehicle control.
WARNING
The effectiveness of ESC can be significantly reduced if other components and systems that affect vehicle dynamics, including but not limited to brakes, tires, and other systems mentioned above, are not properly maintained or functioning.
x Always remember that vehicle alterations or modifications can affect the functioning of the ABS, BAS, ASR, EDL, and ESC systems.
x Changing the vehicle suspension or using an unapproved tire/wheel combination can change the way the ABS, BAS, ASR, EDL, and ESC systems work and reduce their effectiveness.
x The effectiveness of ESC is also determined by the tires fitted, Tires and wheels.
All 4 wheels must be equipped with identical tires in order for ESC and ASR to work properly. Differences in the tread circumference of the tires can cause the system to reduce the engine power when it is not expected.
If ABS is not working, ESC, ASR, and EDL will also not work.
You may hear noises when these systems are active.
