eason

Finally rain season arrive, after 3 months of sunshine, I have to chance to really play with the C230K in the rain. I did some 90 degrees left and right turns with 2nd gear (mine is an auto) w/ESP off, I enter the turn with appox 40km/h then accelerate thru the conrer. The tail slide a little bit, as I keep accelerating with 2nd gear, the car swings out more to a point when ESP kicks back in to keep the car stable. I have also try to turn with different style. 1) Just turn the steering wheel into the turn and accelerate in the middle of the turn. 2)Counter-steer when the car swing the tail out and keep accelerating. With both method, the car will still be in control when the ESP kicks in. However, you will experience a more smooth ride with the counter-steer method. I haven't try the dyno mode, but I think I will try in the future.

avlis

I could be wrong, but I don't think ESP kicks in when the button is off. The light still flashes but, the stability program is disabled. I drove on a snow covered parking lot with ESP off and I was able to spin the car out.

Lynn

avlis is corret. IF ESP is off, it will not do anything.

MB-BOB

There was discussion several months ago whether pressing the ESP switch truly disengaged the system (completely). Several folks weighed in on the concept that Brake Assist, ABS and some elements of Traction Control remained ON even if ESP was disengaged from the dash. Hence, if you go too far over the limit, these background systems will kick in to attempt to recover the car.

The original thread concerning this was posted by mbtech208 and was entitled "Smokey Burnouts for W203 Owners." However, my search to pull up this thread doesn't work anymore. (Apparently there is a time limit on old posts).

Anyway, here's a more recent thread on the topic...

https://mbworld.org/forums/showthrea...nouts+for+w203

In sum, to completely turn off all driver aids, as well as get a more detailled guesstimate of your oil level, you might want to try this procedure.

young

here's that thread... the info is also in the faq.
https://mbworld.org/forums/showthrea...=&threadid=854

eason

From my driving experience, pressing the ESP button on the dash will disable the traction control; therefore, the both rear wheels can spin at the same time. However, when the ESP is off, the stability assist is still on. Once the car senses the wheels are not spining at the same time, it will help to stable the car by applying brake to an individual wheel. I am not an ESP expert so I maybe wrong, but this is what I think and feel from driving the car.

avlis

I have to totally disagree. There is a huge difference in stability with the ESP off: https://mbworld.org/forums/showthrea...&threadid=3463

Traction control (with an exception below) and stability programs are disabled. Otherwise, what's the point in having the button?

I'm aware that there are still some aspects of ESP still running even with the button off, but I think it's limited to just mimicking a limited-slip differential. Dyno mode turns even that function off and allows the smokey "one-wheeled" burnouts.

session

speaking of traction control, anyone know what type of rear end differential the coupe has?

avlis

As far as I know, it's open. The ESP tries to make it a limited slip. Dyno mode makes it one-wheel-drive.

Lynn

avlis is still correct. When ESP is off the car will do absolutely nothing to recover itself. Yes ABS, Brake Assist an ASR are still on. ASR is a poor substitute for a real limited slip differential. ASR uses the brakes to control wheel spin when accelerating. ASR will try to have both rear wheels spinning equally. ABS and brake assist will do nothing until the brakes are applied.
Applying the the brakes in a corner, especially when in a skid or slide, with ESP off is very stupid and dangerous if the car is still under the driver's control. If contol has been lost, the driver mights as well stomp on the brake pedal.

session

i wonder how this works in the differential... perhaps it electronically controls whether the pinion gears lock or not. how does ESP control how much torque is applied to each wheel if it's an open differential?

Lynn

It doesn't work in the differential. ASR uses the rear brakes to emulate a limited slip diff.

session

ah, makes sense i suppose. it would be cool if it had a real limited slip differential

patronus

I regularly autocross my C240 with ESP off. I think that there is still some residual braking effort by ESP with the switch off, however it cannot usually keep up with the momentum of the car. I am certain that the throttle portion of ESP is turned off.

Therefore, one can still spin the car with ESP off, but it takes more work than with no ESP present at all (Dyno mode or a car w/o ESP).

Lynn

I agree. There is no substitute for the real thing.

avlis

Lynn, what does ASR stand for? I didn't know it had a name. Anyway, thanks for clarifying the ABS, ESP, & pseudo-limited slip nomencalture!

Lynn

ASR stands for Automatic Slip contRol. Don't ask me why its not ASC, that would make more sense to me also.

http://www.mbusa.com/brand/container...30K&class=03_C

patronus

Many of these acronyms are translated from German.....

eason

So that means with the ESP off, the computer will not hold down the engine power? When I was in the middle of the turn (the car is sliding) I gas about 3/4 throttle and counter-steer; however, I feel the engine is decreasing the power and grips the road. The road was wet and I don't thing the tire can get back control while it is still sliding and I gas it at the same time.

MB-BOB

Thanks, young. What a difference an "e" makes. I was searching on "Smokey burnouts..." Instead it's "smoky..."

Keeping track of these old threads is difficult when you have to remember the spellings, too...

preyx

To me, the car still feels different between ESP and dyno-mode when attempting fast turns. The wheels will make skidding noises with ESP-off, but it seems the car won't relinquish full control.

Lynn

When ESP is off ASR is still on, so you are getting the pseudo-limited slip differential effect. Nothing else is happening. The throttle is not being closed by the computer. The ESP is not trying to stop the skid or slide.

In dyno-mode, you now have an open differential, just like a '39 Ford. Why anyone would want to drive with the car in dyno-mode is beyond me.

MarkL

Guys, I agree w/ Lynn. Some people are a little confused I think between the functions of traction control and ESP. Traction control, however it is applied by the mechanics of a car, simply tries to control drive wheel spin by either limiting engine output or braking the spinning wheel. It is a "dumb" system which simply uses the ABS sensors on the drive wheels to detect spin. ESP, on the other hand, is a much more sophisticated setup. In addition to the "regular" sensors, yaw sensors determine whether the car is following its intended path by noting such things as steering wheel angle, etc. When the system detects yaw, or spin, it applies braking to the appropriate corner to stop the spinout.

The ESP button on the dash only disables ESP. Normal traction control is still engaged. This has been attested to by several techs over the last year or so. To totally disable traction control, you need to follow the procedures mentioned before (dyno mode). Now, if you're "playing games" and trying to spin out, and you notice some braking etc. even with ESP switched off, I'm assuming you're also getting drive wheel spin which would be detected by the normal traction control system and would be attempted to be stopped. There's no mistaking the action of ESP -- try it around a wet corner one day. The spinout is stopped almost immediately and the car goes back to straight line tracking.

Accord

If the conditions are dry, ESP always remains off, if the conditions are wet, ESP will always remain on. ESP doesn't completely shut off, unfortunately .

patronus

MarkL, I think you are correct. Now that I think about it, inducing wild oversteer during autocross is met with some resistance (ASR), yet wild understeer is as, well, wild as you want to make it.

Good assessment.