ESP failed to stabalize car - Page 2 - Mercedes-Benz Forum

Reply
 
LinkBack Thread Tools Display Modes
post #11 of 32 (permalink) Old 01-11-2010, 02:04 PM
BenzWorld Elite
 
johnhef's Avatar
 
Date registered: Mar 2007
Vehicle: Too Many
Location: Frederick, MD
Posts: 2,589
Mentioned: 0 Post(s)
Quoted: 0 Post(s)
Send a message via AIM to johnhef
frost- it should be easy enough to test. find a large parking lot and accelerate from a stop while making a turn to try and get the back end to whip out. if it does, then you are correct in that ESP is not working.


Master Certified 10 years MB tech
1980 500SE Euro
1981 500SEL Euro
1982 380SEL
1983 500SEC Euro
1983 300TD
1984 500SEC - parts car
1984 300TD Euro
1985 190E 2.3-16 Euro
1986 190E 2.3-16
1986 190E 2.3-16 Lemons
1987 300D
1999 C230K
2003 C320T-4
2003 E55
johnhef is offline  
Sponsored Links
Advertisement
 
post #12 of 32 (permalink) Old 01-11-2010, 09:19 PM
BenzWorld Elite
 
Date registered: Sep 2008
Vehicle: 2002 E430 4-Matic
Location: Chicago - North Surburbs
Posts: 1,330
Mentioned: 0 Post(s)
Quoted: 33 Post(s)
Quote:
Originally Posted by Frost View Post
Last night I was driving in rain on the open road doing just under 120km/h. The road was quiet, visibility was good and no potholes in the road as well so I reckon that I wasn't driving at an insane speed giving the road and weather conditions.

When the road made a slight turn, I was noticing that the car's rear end started to skid slightly. I started to brake ligthly to reduce speed as I figured that the road was probably abnormally slippery due to the rain and that's when things went from bad to worse.

The car started to swerve sideways from left to right. I started to brake harder and tried to regain control over the steering wheel but the car just swerved more violently from left to right. I then decided to brake as hard as I can and try to keep the car on the road but it did not help at all. The car spin around a few times and eventually came to a halt on the side of the road in the mud.

What frightened me the most from the whole ordeal is that I noticed that the ESP did not even come on once during the skid. Isn't ESP suppose to prevent exactly this from happening?

I know the ESP is working because shortly after that we were driving on a muddy road to a friends house and the ESP came on almost constantly to regain traction in the mud.

The car is a 2004 C-class.
I think you are confusing the functions of ESP, ABS, and Traction Control. Keep in mind there is a hierarchy between these systems and all three can't work at the same time. For example if you slam on the brakes ABS will try to minimize wheel lock on all 4 wheels. Under these conditions ESP can't compensate for yaw so it deactivates.
It was traction control that helped you in the mud, not ESP or ABS.

I suspect what happened was that when you first went into a slight skid, ESP tried to help, but you were probably hydroplaning and as a previous poster said...Mother Nature took over. You then slammed on the brakes totally disabling ESP.

One thing to keep in mind when you find yourself in a similar situation...whether or not you have ESP or ABS. When you encounter a slippery condition you need to remember that your tires have only a given amount of available traction. You can use 100% of that traction to stop, or 100% to turn. If you decide to use 50% to stop, then you only have 50% to turn. In your case you decided to use 100% to stop...0% remained for turning, thus the spin.
Figuero is offline  
post #13 of 32 (permalink) Old 01-12-2010, 07:52 AM
BenzWorld Newbie
 
Date registered: Dec 2009
Vehicle: C300 4MATIC, Rover
Location: CA dreaming
Posts: 1
Mentioned: 0 Post(s)
Quoted: 0 Post(s)
Oversteer

Hi,
As others have said, your problem was oversteer that was made far worse by braking. No ESP/TC/ABS can fix this for you at that point. Braking transfers more weight toward the front of the car, making the back lighter and worsening the rear traction and causing your total loss of control and spin. The correct way to handle this situation in the future would be to gently decrease your pressure on the gas and continue your turn into the corner. If you have 4WD/AWD, and you believe, based on how the car is handling, that you still have good traction, you can also gently accelerate. This will cause the wheels with good traction to propel your car forward in the direction that you want and can correct the oversteer without spinning out. I would not do this with a RWD Benz however. The results would be unpredictable, just gently decelerate. If you abruptly decelerate, you can also transfer weight to the front and worsen the oversteer to the point of losing control. If you were truely hydroplaning, you would have likely had no control at all and propelled straight on in the direction that your car was headed when you started to hydroplane and into the guardrail, field, etc. (as opposed to spinning out)
I will never own a non 4WD/AWD car again because of what I believe is better control with AWD in certain situations. If you can have better control, you can avoid some accidents. That is a variable I can control and it is worth the extra cost to me, including limiting some engine options, etc.
Before the wife and kids era, I had a certain German AWD sports car and I used to drift (forcing the above situation) all the time. Loads of fun, but more tricky with modern AWD, the computer and system usually compensate too fast, and you need a lot of power. I actually did it the other day test driving an AWD M45 on some windy back roads by accident. It drifted pretty easy for an AWD, the tires must really suck. After I did it a couple more times the dealer asked if I knew what I was doing. I just laughed. It did catch pretty quick when I hammered the gas coming out of the turn.
Now that you understand what happened, you can be better prepared in the future. Tell your wife/GF/children about what happened and how to avoid the same problems. I don't want them hitting me some night!
One of the problems with driving in the US is that no one really learns how to drive correctly. My father took me out all the time, in all driving conditions, for a whole year before letting me drive alone. Personal experience behind the wheel is the key to avoiding accidents, and situations that cause accidents. The above is true BTW, I have a professional interest in pediatric trauma and there is ongoing research regarding what causes new drivers to have accidents and near misses. It's really interesting, and amusing. The key is personal experience, and you can't get that by driving around with dad in perfect conditions on suburban streets for a few weeks and some poor drivers ed classes at school.
Regards,
Dr.Brian is offline  
post #14 of 32 (permalink) Old 01-12-2010, 08:32 PM
BenzWorld Elite
 
bsmuwk's Avatar
 
Date registered: Jun 2008
Vehicle: Depends on the week
Location: IL / WI
Posts: 3,695
Mentioned: 1 Post(s)
Quoted: 30 Post(s)
Quote:
Originally Posted by Dr.Brian View Post
Hi,

One of the problems with driving in the US is that no one really learns how to drive correctly.
Bingo.

The problem being in the US, there is no situational training. There should be more emphasis on maintaining control and going forward with the correct driver input to try and regain control over the vehicle. But hey, we're in the US. Anyone can get a driver's license. now, i'm a youngster myself (17) and i think we need more schooling in driver's ed.

Prior to me getting my driver's license my dad took me on a very nice wide open plains dirt road and told me to hold a drift with his tuned 81 nissan 280zx turbo. He said if I could hold a drift he'll go with me so I can officially get my driver's license (all my learning hours and whatnot were done). In his thinking, if I'm able to maintain control over a 5 speed car and properly apply throttle, brake and clutch on a dirt road going sideways in a car with balls that would get stuck in the grand canyon, i should be able to control a slushbox slowpoke whipping around a little on wet pavement. mind you, i had no idea how to drift other than on the video games. beautiful curve in the road that was.


let's just say i got my license.....play video games, they're more realistic than you think!

☆ ★ A R T I S A N ☆ ★ ☆ ★ A R T I S A N ☆ ★
Chicagoland Mercedes Facebook Group: https://www.facebook.com/groups/mbclubchicago/
Join the W124 Buy/Sell/Trade/Chat Group on Facebook : https://www.facebook.com/groups/224626884381433/
http://artisanexcite.blogspot.com/
Mercedes Diesel Injector Servicing: http://artisanexcite.blogspot.com/p/...servicing.html

Last edited by bsmuwk; 01-12-2010 at 08:36 PM.
bsmuwk is offline  
post #15 of 32 (permalink) Old 01-13-2010, 04:56 AM Thread Starter
BenzWorld Junior Member
 
Date registered: Aug 2009
Posts: 26
Mentioned: 0 Post(s)
Quoted: 0 Post(s)
(Thread Starter)
I agree that we need more training in this regard when getting a driver's license. I live in South Africa and we don't get such training either when obtaining our driver's license, which I think should actually be made a requirement since I recently read in a newspaper article that we had 13 times more accidents on our roads than in the US.

Interestingly enough, in Finland it is a requirement to do a slippery driving course prior to getting your license (Driving licence in Finland - Wikipedia, the free encyclopedia).

Well I still wanted to know if my car's ESP works properly even though the manual says that a warning light will come on if it's not working. So I took the car for a spin on a quiet road and found that the car does actually allow you to drift a small bit before the ESP kicks in. Once the ESP kicked in, I could hear and feel the one wheel break and the car immediately regained complete control. This was at about 60km/h and I kept my foot on the gas pedal as I was going in the turn.
Frost is offline  
post #16 of 32 (permalink) Old 01-13-2010, 06:04 AM
Outstanding Contributor
 
eric242340's Avatar
 
Date registered: May 2007
Vehicle: Zotye Auto 1.5T T600 2016
Location: The wild west of the Far East
Posts: 52,187
Mentioned: 3 Post(s)
Quoted: 291 Post(s)
Interesting read and thanks for the post.

With ESP (electronic stability program) there is a sensor in the center of the car known as the lateral stability sensor. I hope I can explain this correctly for you.

Your car began to slide whilst taking a bend on a wet road at 120kmph and if you had NOT braked the lateral sensor would have reacted to this and enabled the ESP. ie, if you kept the accelerator on then the ESP would correct for you but you did what most folks would do, panic and brake.

The ESP computer is programmed for a certain amount of drift before coming in. By hitting the brake you overrode this parameter therefore the light did not come on and the ESP did not function but your ABS took over to control the car as you pressed the brake harder and harder.

Next time you try this, even experimental, hit the gas pedal instead and you will be surprised at the result.

ERIC.

___________________________________________
"I am enclosing two tickets to the first night of my new play; bring a friend, if you have one."
- George Bernard Shaw to Winston Churchill.

"Cannot possibly attend first night, will attend second ... if there is one."
- Winston Churchill, in response.
eric242340 is offline  
post #17 of 32 (permalink) Old 01-13-2010, 11:43 AM
BenzWorld Extremist
 
600amg's Avatar
 
Date registered: Feb 2007
Vehicle: 2005 E55 Designo
Posts: 888
Mentioned: 0 Post(s)
Quoted: 1 Post(s)
Post ASR

not as lucky with the old ASR. i grew up with powerful cars. At 17 a 70 440 Super Bee, 22 70 Charger RT 440+6 and at 23 70 Roadrunner Conv 440+6 4 spd and so on....In Winter, if the Merc gets sideways at 120km/h at one point i will put the gas to the boards & bring it back, ASR says NO. Being born in the land of Ice i can say that ASR is only good for keeping your rims true at low speeds in winter, the rest of the time it hinders any attempt by an experienced driver the correct the situation. On the other side of the coin, ABS saved my ass a few times, you just have to be not shy to put the brake pedal to the boards.
600amg is offline  
post #18 of 32 (permalink) Old 01-15-2010, 05:02 AM
BenzWorld Senior Member
 
Emre-K's Avatar
 
Date registered: Jun 2009
Vehicle: '87 190E 2.3-16
Location: Manhattan
Posts: 411
Mentioned: 0 Post(s)
Quoted: 3 Post(s)
Quote:
Originally Posted by Frost View Post
When the road made a slight turn, I was noticing that the car's rear end started to skid slightly. I started to brake ligthly to reduce speed as I figured that the road was probably abnormally slippery due to the rain and that's when things went from bad to worse.
As you've discovered, once your car starts to oversteer, pretty much the worst thing you can do is hit the brakes. That only shifts even more weight off the rear axle, which will increase your yaw angle dramatically.

Quote:
Originally Posted by Frost View Post
... it has become somewhat of a habit of mine to see when the car tries to control itself)...If the ESP light did come on and the car was still skidding then I would accept the fact that the car tried to control itself but was unable to, but the problem is that it seems as if the car never even realized what was going on.
If you're relying on electronics to keep your car under control, you'll always be behind the game. There's a real limit to what they can do. Physics is physics

Quote:
Originally Posted by Frost View Post
I did some research on Wikipedia (Oversteer - Wikipedia, the free encyclopedia) regarding how ESP works during oversteer and understeer and I know now that by braking during the drift, actually worsened the situation...So now I know what to do when something like this happens again.
Unfortunately, knowing what to do and actually doing it are two different things

What we teach our students in our high-performance driving schools is that when your car starts to slide (whether oversteer or understeer), your first instinct should be to gently unwind the wheel coupled with ever-so-gently lifting off the throttle (what we call "feathering the throttle"). Basically, you keep your foot on the throttle and look where you want to go. That way, you naturally unwind the steering wheel just the right amount...without over-correcting. Over-correcting is what leads to the fishtail situation you experienced.

This takes TONS of practice because it goes against every instinct in your body!

Quote:
Originally Posted by 600amg View Post
Being born in the land of Ice i can say that ASR is only good for keeping your rims true at low speeds in winter, the rest of the time it hinders any attempt by an experienced driver the correct the situation.
I agree completely. I've been involved in motorsports for over 10 years now, including rally and ice racing. When I drive a car with electronic stability and traction control, I go nuts. I want a car to do exactly what I tell it to do. This is especially important to me when the car is sliding: the last thing I want is for the car to fight my inputs.



1987 W201 190E 2.3-16: Vintage racer
1990 C124 300CE coupe: Daily Driver
1991 Peugeot 405 Mi 16: Weekend Toy
Emre-K is offline  
post #19 of 32 (permalink) Old 01-19-2010, 05:41 PM
BenzWorld Junior Member
 
Date registered: Sep 2009
Vehicle: Too many to list.
Location: North Hollywood, CA
Posts: 29
Mentioned: 0 Post(s)
Quoted: 0 Post(s)
Smile

Braking during the side skids was an absolute no no! The title of this thread should be changed to "Driver failed to drive properly during wet conditions."

120km/hr is quite a high rate of speed during a wet turn.

A lot of other cars other than a C-Class probably would have rolled over during the incident!

Lakers. . . NBA World Champions!!! #1
Lakeshow24 is offline  
post #20 of 32 (permalink) Old 02-09-2010, 02:27 PM
BenzWorld Member
 
01rollas's Avatar
 
Date registered: Jan 2008
Vehicle: 2004 E500
Location: NW San Antonio, Texas
Posts: 194
Mentioned: 0 Post(s)
Quoted: 0 Post(s)
depending on the factory setting you can have the dealer re-set the intervention level and have it set higher. my car always did horrible on wet pavement and when i took it back to MB of SD i had them make it more sensitive and so now it turns on more than it would have done before. even then if the car starts to skid don't even touch the brakes just let the gas go and retain the steering as much as you can. it was worked for me in the past from front to rear wheel drive cars.

Semper Fi
01rollas is offline  
Sponsored Links
Advertisement
 
Reply

  Mercedes-Benz Forum > General Mercedes-Benz Forums > MB Safety & Testimonials

Quick Reply
Message:
Options

Register Now



In order to be able to post messages on the Mercedes-Benz Forum forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.

User Name:
Password
Please enter a password for your user account. Note that passwords are case-sensitive.

Password:


Confirm Password:
Email Address
Please enter a valid email address for yourself.

Email Address:
OR

Log-in











  • Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
     
    Thread Tools
    Show Printable Version Show Printable Version
    Email this Page Email this Page
    Display Modes
    Linear Mode Linear Mode



    Similar Threads
    Topic Author Forum Replies Last Post
    Car failed Smog. Any ideas? amejia3620 W202 C36 AMG, C43 AMG 1 05-19-2009 03:19 PM
    CLK55 ESP Light and Car Stalls cali55 General AMG 5 01-23-2009 10:28 PM
    How do i get my car into Dyno mode? (no ESP/ABS/ etc.) timmynabenz C209/A209 CLK-Class 1 09-12-2008 06:32 AM
    ESP Failed - How should i fix it qhk333 C209/A209 CLK-Class 3 11-29-2007 08:00 AM
    Esp Shuts Car Down@ 80mph Need Help meen 55 W210 E50 AMG, E55 AMG 2 05-28-2007 02:29 AM

    Posting Rules  
    You may post new threads
    You may post replies
    You may not post attachments
    You may not edit your posts

    BB code is On
    Smilies are On
    [IMG] code is On
    HTML code is Off
    Trackbacks are On
    Pingbacks are On
    Refbacks are On

     

    Title goes here

    close
    video goes here
    description goes here. Read Full Story
    For the best viewing experience please update your browser to Google Chrome