The ESP system in the new mercedes c class
 

I have just bought a used 2008 mercedes c class (new shape). I have read the manual but do not understand what the ESP system is for and how or when to use it. I tried to contact the salesman who sold the car to me to get further clarification, but he did not seem very helpful.

So could someone please explain what the ESP is and when/how to use it, or when not to use it?

Thanks in advance for your cooperation.

ESP stands for "Electronic Stability Program". Most manufacturers have some form of this system but it's usually called "Electronic Stability Control".

You don't actually have to do anything yourself really. What it does is have the computer in the car brake each wheel individually when you are in a slide to straighten you out again - mainly to help avoid/minimize the damage to you and the car in the event that you are headed for a crash.

Some people like to disable it to slide the car (and press that button on your dash), yet it does not fully disable it. It only limits it somewhat in comparison to other manufacturers' systems.

But yeah, you don't need to do anything with it. It's a safety aid in your car.


The other two programs are ABS (Anti-Lock Braking Systems), and ETS/TSC (Electronic Traction System). Those use the brakes to keep traction during braking and acceleration respectively.

^^ what he said. The system measures yaw rate, steering angle, and speed to calculate whether you are going in the direction of where your steering wheel should lead you do go. If there is a difference, then it can brake each individual wheel (or more) to correct the difference.

And if you are wondering why the car then has this ESP button at all, you can read instructions from your manual (mainly useful to switch off ESP when trying to get off from thick snow of soft sand where the wheel initially needs to slip to gain better grip).

A good video explaining what all the above are:

http://www.youtube.com/watch?v=wR1SSxpKitE

Maybe off the topic (I hope not much as this is still ESP thread) but I tried Clicking that ESP button On/off (almost 30 cm of snow and I needed to take my car out of my parking lot) but the light remains there (No indication of On/off). Is it common to all or should I check my switch?

The indication that the ESP is off is that the orange triangle lights all the time. When ESP is on, the triangle only flashes when the ESP is working.

Thanks Wargen for your quick reply. Yes, I do see that triangle flashing while driving but when I press that ESP button, it doesnt give me a clue whether it's ON or Off. I mean like other buttons for example : Parktronic - when you switch it off, the light on that button goes off but ESP light always remains on.

Hey Wargen, just checked again and can confirm it works as you mentioned. There's no red light on the button but when I make it On/Off, the yellow triangle goes on/off. Thanks.

I would have preferred a more technical presentation. But do others believe in the ASR part? Just like ASR would add friction between the tyre and the ice (road). To some extent ASR improves grip when wheel slip is avoided but it does not mean the car would move on for ever as long as the engine power is sufficient to keep it going. If the car was able to climb the road with ASR (ESP) on, it would have done it from a good initial speed and with smooth gas pedal operation.

I believe it! I believe that computers can do things that are impossible for the humans to do. If Tiff doesnt have enough feeling in his throttle foot i guess you can say that ASR is better than any human.

ASR doesnt provide more friction but its better in finding the grip that any surface can provide, so with the same initial speed ASR would still do better. It wont climb forever because at some point there wont be enough friction but if the friction is there ASR will be better in finding it than your foot.

Yes I certainly agree that the computer is better in finding the grip and making most of it but in this slope test in my opinion the friction should be constant throughout the slope and if there is enough friction to keep the car moving, no ASR action is needed.

Or do you think it is a combination of the kinetic energy the car initially has plus the available friction, where friction alone is not sufficient to keep the car climbing at steady speed? In this scenario ASR would be needed to gain the maximum effort out of the kinetic energy and limited friction.