Sunday I was on a short drive in my 2000 ML320. It was clear and dry. I was backing out of a level, well packed gravel driveway, and backed into a shallow grassy ditch running along the edge of the driveway.
The front left wheel stayed on the driveway. There was no part of the frame touching the ground anywhere. I tried to pull forward onto the driveway, and the front left wheel just sat there spinning and smoking. I could not hear the system working, as I have heard before. I tried again in "Low Range", with the same results. It took three people to push me forward up onto the driveway, with the front left tire spinning the entire time. The ML was absolutely helpless!! I honestly think that a two wheel drive, rear wheel drive car would have done better.
One time last year, I was offroad and ended up in a situation where the right rear wheel was several inches off the ground while I was backing a trailer on uneven hillside terrain. I unhitched the trailer, and with the right rear wheel still several inches up in the air, I was able to drive right out of the situation. I could hear the system working, and I was very impressed with how well it worked.
Is there something that could have totally disabled the system since then? I checked the fuse relating to the ABS, and it was fine.
Thanks for any advice you can give me, before I take it into the dealer. It is still under "extended warranty" but was wondering what to expect before I take it in.
Well this weekend, I tried another test. I took one of those ramps you drive up on to work under the vehicle, and put it on a 4"x12" block of wood to raise it a little higher, and put it in front of the left front wheel.
I drove slowly up onto the ramp, and before I reached the top of the ramp, the front right, and left rear wheel started spinning on the gravel drive. They both continued to spin for quite some time. The yellow triangle in the dash did flash on and off the entire time. The traction control system never did engage, and I was unable to reach the top of the ramp.
I backed off, turned off the ML, let it set a minute to "re-boot" or whatever, and tried the test again, with exactly the same results the second time.
My foot was not on the brake, and my foot was on the accelerator pedal.
My ML320 is at the dealer at this time, and I will see what they report.
This makes me wonder how many ML drivers know whether their traction control system is working or not???
Benzark - 9/13/2004 9:03 AM
I drove slowly up onto the ramp, and before I reached the top of the ramp, the front right, and left rear wheel started spinning on the gravel drive. They both continued to spin for quite some time. The yellow triangle in the dash did flash on and off the entire time. The traction control system never did engage, and I was unable to reach the top of the ramp.
George,
it worked as it is supposed to work. When the triangle flashes with your foot on the accelerator, this means the wheels in the air are braked. They do not completly stop turning. In high range the difference speed is 3 MPH, so if the wheels on the ground are a 0 MPH, the ones in the air turn at most 3 MPH. If that's too much, one can engage low range. In that case the difference speed is only 1.2 MPH. This is decribed here:
I guess I still have much to learn about the system. I don't understand why the vehicle did not make it to the top of the ramp. The diagonal wheels were spinning, but it also did not drive on up the ramp, it just sat there. Maybe I just did not give it enough gas, because I did not want to run up the ramp, and over the top of it, but I gave it what I thought was plenty of time to engage. I also did not hear any of the noises the system made the time it successfully extricated me from a difficult situation.
It seems that perhaps some of the system requirements might be counter-intuitive. If you are rolling backwards into a ditch, and put on the brakes to stop backwards movement, and the system will not work if the brake pedal is depressed......
Thanks again, for your replies and input, and I will go back and study up on the system, from the link you posted to your website.
George
P.S. I also currently own a 1973 Land Rover, a 1977 Dodge Power Wagon, and a 1988 Suzuki Samurai. It's not like the ML320 is my first 4 wheel drive. I just need to learn more about it.
Benzark - 9/13/2004 10:19 AM
If you are rolling backwards into a ditch, and put on the brakes to stop backwards movement, and the system will not work if the brake pedal is depressed......
George, yes, I can understand your thinking, and the ML's drive system is different from other 4x4 (at least when it came out, now many other manufacturers switch to this system too) and it may take some time to get used to it. The Mercedes M-class and G-class driveline design engineer would say: "Let the car do the work" meaning to keep a steady foot on the gas in tricky situations, and off the brake predal.
It sure would be nice if there was an "electronic differential lock".
Hit a switch that tells ETS to "Ignore all other inputs...just send power to all four wheel evenly...ignore that wheelspin!...trust the driver to let all four wheels spin until the car grabs hold of something..trust the driver to not turn on when on dry pavement..."
__________________
"I feel much better ever since I gave up hope."
As I suspected, you were right! Everything checked out "normal" at the dealership. Of course they could not explain it, the way you can. They suggested perhaps it was some sort of rollover protection kicking into action. But they said that they tested several other ML's and they all acted the same way under the same conditions. They also had a steep hill behind the dealership, and they said it worked as it should climbing straight up a steep hill. (Perhaps not exactly real world conditions) but I guess that I am satisified that all is working as it was designed to work.
George, glad I could help. I hope 4ETS works out for you. I just checked in with the folks who make the system for the M-Class. They now supply all these cars:
* Audi Roadster TT (marketed as Electronic Stability Program)
* BMW 3-Series (Dynamic Stability Control)
* BMW Z4 (Dynamic Stability Control)
* Chrysler 300 (Electronic Stability Program) ... NEW PROGRAM
* Chrysler Crossfire (Electronic Stability Program) ... NEW PROGRAM
* Dodge Magnum (Electronic Stability Program) ... NEW PROGRAM
* Ford Escape Hybrid SUV
* Ford Expedition (AdvanceTrac)
* Ford Explorer (AdvanceTrac)
* Infiniti FX 35 (Vehicle Dynamic Control)
* Infiniti FX 45 (Vehicle Dynamic Control)
* Jaguar S-Type (Dynamic Stability Control)
* Jaguar XJ Series (Dynamic Stability Control)
* Jaguar XK Series (Dynamic Stability Control)
* Jeep Grand Cherokee starting with MY2005 (first Jeep)
* Lincoln LS (AdvanceTrac)
* Mercedes M-Class (Electronic Stability Program, since 98, ESP since 99)
* Mercedes C-Class (Electronic Stability Program)
* Mercedes Coupe CLK (Electronic Stability Program)
* Mercedes Roadster SLK (Electronic Stability Program)
* Mercury Mountaineer (AdvanceTrac)
* MINI Cooper (Dynamic Stability Control)
* Nissan Frontier (Vehicle Dynamic Control)
* Nissan Murano (Vehicle Dynamic Control)
* Nissan Pathfinder Armada (Vehicle Dynamic Control) ... NEW PROGRAM
* Nissan Titan (Vehicle Dynamic Control) ... NEW PROGRAM
* Nissan Xterra (Vehicle Dynamic Control)
* Porsche Cayenne (Porsche Stability Management)
* Toyota Sequoia (Vehicle Stability Control)
* Volkswagen New Beetle (Electronic Stabilization Program) ... NEW PROGRAM
* Volkswagen Touareg (Electronic Stabilization Program)
* Volvo S70/V70/C70 (Dynamic Stability and Traction Control)
* Volvo S80 (Dynamic Stability and Traction Control)
* Volvo S40/V40 (Dynamic Stability and Traction Control)
* Volvo S60 (Dynamic Stability and Traction Control)
* Volvo XC90 (Dynamic Stability and Traction Control)
PS. This list might not be complete, I might have missed some, or listed some incorrectly.
I am sure that it will work out for me just fine. I thought that it had failed without any warning. I was unaware of the "details" of the system operation parameters. It has worked for me before in real life situations. It "failed" me, due to "operator error" in the simplest of situations, which sort of "freaked me out".
I don't know what we would all do without this "sharing of information on the discussion boards"!
What an impressive line-up of users of the system! That should speak volumes in and of itself!
Linear Mode
