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2009 ML350 4Matic - What is 470 SEMI-ACTIVE ROLL STABILISATION (SEMI ARS)
I understand it reduces body roll by reading data from steering angle, yaw, acceleration/deceleration sensors...but what does it actually adjust to reduce the roll?
And what does "Semi" mean in this case?
The vehicle does not have AirMatic that I am aware of.
Do you have a button on the lower switch panel that looks like a shock absorber?
If yes it could be a variation of adaptive damping. However if you also have a button to raise the vehicle then you have Airmatic.
Another quick way to tell if you have Airmatic is to look under the rear end... If you have traditional coil springs, then no Airmatic, but if you have two rubber barrel shapes where the springs should be then you have Airmatic.
After eliminating actively adjusting the shock absorber damping (ADS) or adjusting ride height (Airmatic), and noting that the latter doesn't act fast enough to make a difference through most turns in which one would want it, there are only two possibilities remaining. One is reducing engine output and the other is modulating the brakes, using the ABS system. This would be the electronic stability program (ESP), which is mostly known for traction control or pseudo-four-wheel-drive, does quite a bit else that the driver is seldom aware of. For example, when towing a trailer, it assists in stabilization.
Roll stabilization might be accomplished by slightly feathering an inside wheel's brake; for example, in a turn, lightly dragging the inside wheels might help rotate the vehicle and reduce body roll.
I'm no mechanical engineer but wouldn't stiffening the outside shock and softening the inside shock in a turn reduce body roll? Airmatic shocks ought to be capable of this.
I'm no mechanical engineer but wouldn't stiffening the outside shock and softening the inside shock in a turn reduce body roll? Airmatic shocks ought to be capable of this.
I'm no mechanical engineer but wouldn't stiffening the outside shock and softening the inside shock in a turn reduce body roll? Airmatic shocks ought to be capable of this.
Shock absorbers only provide resistance to movement. Their proper name is "damper"; they provide friction that stops the weight (the vehicle) on the spring from continuing to bounce up and down after it is bumped. So what you suggest would have a tiny effect on the outside wheels - and the softening would help the inside wheels push the body into roll, also just to a tiny extent.
Of course, at the limit, if you simply locked the shock absorbers, you wouldn't have a suspension anymore ...
In a way, the dampers actually are "shock absorbers", in that they ultimately absorb the energy from bumps. If the vehicle bounces and then settles down, the oil inside the shock absorber has heated up a little from absorbing the energy. Baja trucks have cooling systems for the shock absorber oil.
Go to your local parts counter and ask for a set of "energy absorbers" for your car. Unfortunately, we're stuck with the name now.
Incidentally, the Airmatic shocks are perfectly ordinary. Only if one has the Active Damping System is anything special happening; the valves inside those shocks are adjustable.
Vehicles of this era use the ABS system to brake the outside wheels in an attempt to reduce the sharpness of the turn and prevent a roll.
Ah, very good. The opposite of what I speculated.
In other words, if you swerve to avoid something, the ABS will assist you in hitting it. Just kidding, better than rolling the vehicle.
ABS (ESP) does something else noteworthy. I once did a panic stop and found that the ABS took over braking for me. "Oh, you REALLY want to stop? Let me be of assistance."
If your car has basic TPMS, ABS derived system, then that's option code 470.
TPMS with wheel sensors is option code 475.
ESP, which your car should have and includes ABS, performs the functions described by braking individual wheels to control yaw and indirectly roll, is option code 472.
Put another way, option code 470 is unlikely to be anything more interesting than TPMS.
If your car has basic TPMS, ABS derived system, then that's option code 470.
TPMS with wheel sensors is option code 475.
ESP, which your car should have and includes ABS, performs the functions described by braking individual wheels to control yaw and indirectly roll, is option code 472.
Put another way, option code 470 is unlikely to be anything more interesting than TPMS.
Hmmm. Well, the VIN decoder says I have option 470 SEMI-ACTIVE ROLL STABILISATION (SEMI ARS), no 472 or 475.
No mention of anything else regarding ESP or traction control...
Yet, I'm getting a tire pressure warning light, and when I scan the car I'm getting 3 codes - 911, 9112 and 9113 - "Signal transmission between at least one wheel sensor and N88(TPM [RDK] control unit) is faulty." This would lead me to believe that you're, no offense, wrong with respect to this aspect of option 470/TPMS.
Hmmm. Well, the VIN decoder says I have option 470 SEMI-ACTIVE ROLL STABILISATION (SEMI ARS), no 472 or 475.
No mention of anything else regarding ESP or traction control...
Yet, I'm getting a tire pressure warning light, and when I scan the car I'm getting 3 codes - 911, 9112 and 9113 - "Signal transmission between at least one wheel sensor and N88(TPM [RDK] control unit) is faulty." This would lead me to believe that you're, no offense, wrong with respect to this aspect of option 470/TPMS.
From your VIN decode in one of the tailgate posts...
Tire pressure monitoring system aka TPMS
No mention at all of semi active roll stabilisation.
The codes suggest that you've a CANBUS issue. It's possible that all the tail gate issues stem from corrosion in the rear SAM.
Removing it, taking the case off and cleaning it and the plugs with contact cleaner and a soft brush may prove beneficial.
From your VIN decode in one of the tailgate posts...
Tire pressure monitoring system aka TPMS Not sure what VIN decoder you're using, but it sems rather generic if it doesn't show the option code #.
No mention at all of semi active roll stabilisation. I literally copied and pasted the text in the thread title from a VIN decoder, "470 SEMI-ACTIVE ROLL STABILISATION (SEMI ARS)"
The codes suggest that you've a CANBUS issue. What codes? The TPMS errors? I mean, maybe, but doubtful. I'm willing to bet it's the actual sensors in the tires that are the problem. But, I really don't want to muddy this thread with trying to diagnose those errors here.
It's possible that all the tail gate issues stem from corrosion in the rear SAM.
Removing it, taking the case off and cleaning it and the plugs with contact cleaner and a soft brush may prove beneficial. I've done all of that and more. Removed it and opened it up and it was spotless. Went ahead and cleaned the board and the connectors with electronics cleaner anyway, just in case. But, again, as much as I appreciate the conversation, this is muddying up this thread that is regarding a different topic.
Anyway, I have my answer to the question asked - I primarily wanted to know if the "roll stabilization" was done via adjusting damper firmness, which it is not.
A quick Google search of the codes you posted all pointed to a Canbus communication issue. From the Vin decode list that you posted in one of the tailgate threads, you do not have wheel mounted sensors.
A quick Google search of the codes you posted all pointed to a Canbus communication issue. From the Vin decode list that you posted in one of the tailgate threads, you do not have wheel mounted sensors.
I don't know why you keep persisting and, again, wherever you're getting your info from is incorrect. If you don't have actual knowledge regarding the subject, could you please stop presenting erroneous information? Someone less experienced than I may actually listen to what you're saying and be steered in the wrong direction.
The 3 actual codes I'm getting are the following;
9111 - Signal transmission between at least one wheel sensor and N88 (TPM [RDK] control unit) is faulty
9112 - Signal transmission between at least one wheel sensor and N88 (TPM [RDK] control unit) is faulty
9113 - Signal transmission between at least one wheel sensor and N88 (TPM [RDK] control unit) is faulty
The TPMS in this vehicle includes sensors in the tires.
In other words, if you swerve to avoid something, the ABS will assist you in hitting it. Just kidding, better than rolling the vehicle.
Yes actually this was a heated discussion in the past as the 164 "failed" the moose test (hard left/right maneuver at ~40 MPH) precisely because the ESP was activating to prevent a rollover condition. There was a video where you could see the left front wheel going into ABS activation to help stabilize things but it of course delayed the return to the right lane resulting in a "failure".
Originally Posted by eric_in_sd
ABS (ESP) does something else noteworthy. I once did a panic stop and found that the ABS took over braking for me. "Oh, you REALLY want to stop? Let me be of assistance."
Yes this is a pre-safe feature where if you lift off the accelerator and immediately go for the brake the vehicle will assume you are taking evasive action and apply 100% brake force along with tightening the seat belts and some other pre-collision things. I've felt it activate a hand full of times over 14 years of ownership.
I don't know why you keep persisting and, again, wherever you're getting your info from is incorrect. If you don't have actual knowledge regarding the subject, could you please stop presenting erroneous information? Someone less experienced than I may actually listen to what you're saying and be steered in the wrong direction.
The 3 actual codes I'm getting are the following;
9111 - Signal transmission between at least one wheel sensor and N88 (TPM [RDK] control unit) is faulty
9112 - Signal transmission between at least one wheel sensor and N88 (TPM [RDK] control unit) is faulty
9113 - Signal transmission between at least one wheel sensor and N88 (TPM [RDK] control unit) is faulty
The TPMS in this vehicle includes sensors in the tires.
If either of those things are wrong or ambiguous I can only apologise but I contributed based on the information you presented.
Post a link to the thread where that PDF document came from - that in no way looks like an official list of all possible codes and I am not certain what is meant by "events".
And what specific VIN decoder did I refer to? I don't recall posting which one/s I used, but maybe I just forgot. There are multiple available and I checked several in case one wasn't decoding things properly.
Post a link to the thread where that PDF document came from - that in no way looks like an official list of all possible codes and I am not certain what is meant by "events".
And what specific VIN decoder did I refer to? I don't recall posting which one/s I used, but maybe I just forgot. There are multiple available and I checked several in case one wasn't decoding things properly.
It was posted in June 2017 in reference to a W164. 175 and is copyrighted Daimler Benz.
That particular Vin decoder is the default mbworld one and is accessible by simply clicking on the the Vin.
https://mbworld.org/forums/m-class-w164/919390-liftgate-latch-wiring-diagram.html
Last Vin gives 470 as semi active roll bar, yet the one above shows TPMS but no option codes, and no SARB.
Obviously the only way to be certain of the actual options fitted is to put your VIN into the genuine EPC and print off the data card.
The specifics of each option code varies subtly for each model as the specifics of each system varies from one model to the next.
I would also counter that unless you're using Xentry or DAS to run your diagnostics, the codes generated may be lost in translation.
FYI, an 'event' is an occurrence of a fault condition that has been registered in the ecu.
Screen shot all three pages of your data card and use DAS or Xentry to give the detailed fault codes from each module and you may get somewhere.
I use Xentry for fault definitive codes and troubleshooting along with WIS for directions. I use iCarsoft MB11 for roadside code reading and clearing low voltage codes. Different code readers produce different results. Factory always trumps aftermarket.
It was posted in June 2017 in reference to a W164. 175 and is copyrighted Daimler Benz. This doesn't help in any way. Post a link to the thread for context.
That particular Vin decoder is the default mbworld one and is accessible by simply clicking on the the Vin. https://mbworld.org/forums/m-class-w...g-diagram.html Right, so a super generic decoder that does not show the option code #s. Relatively useless.
Last Vin gives 470 as semi active roll bar, yet the one above shows TPMS but no option codes, and no SARB. Correct, a better decoder than the generic one on this site. https://www.lastvin.com/ is the primary decoder I used, among others. This is what spurred the creation of this thread to begin with.
Obviously the only way to be certain of the actual options fitted is to put your VIN into the genuine EPC and print off the data card. Then why make comments you deem "factual" based on the most generic decoder you could have used?
The specifics of each option code varies subtly for each model as the specifics of each system varies from one model to the next. Uhmm, OK.
I would also counter that unless you're using Xentry or DAS to run your diagnostics, the codes generated may be lost in translation. Really, you would counter? Counter what? Counter yourself, because again, you're making comments based on who knows what source of information. So far every fault code I've encountered and needed to diagnose/research has been valid and matched that of others who did use Xentry.
FYI, an 'event' is an occurrence of a fault condition that has been registered in the ecu. FYI, an "event" is not a "fault code", i.e. event 1234 is not the same as fault code 1234 makig that document you've been referencing completely false and useless.
Screen shot all three pages of your data card and use DAS or Xentry to give the detailed fault codes from each module and you may get somewhere. Why?
I use Xentry for fault definitive codes and troubleshooting along with WIS for directions. I use iCarsoft MB11 for roadside code reading and clearing low voltage codes. Different code readers produce different results. Factory always trumps aftermarket. Good for you. Yet, you're wrong on so many levels.
Chill out dude. The whole point of these forums is to exchange information. You might not agree with everyone, but some people look at things in a different way and interpret information in a manner you might find contrary. Vague information gives rabbit hole responses.
Xentry offers guided tests for various fault events and fault codes to direct accurate troubleshooting. But it has to be connected to the car being diagnosed. Best anyone can do remotely is look up information on WIS, ideally with the VIN to make the information more focused.
Using TPMS as an example, it's been mandated on vehicles for the best part of 25 years, but there are several different ways of achieving the same result. I know the cost option system on my W221 is different to the basic system on my W164.
So, starting fresh:
The codes you present... Which specific module do they come from? And are there any related codes in associated modules?
Note the parts apply to your VIN and option codes 470 and 475. Your car does NOT have option 475. From the actual data card. TPMS antenna location for 470. The wheel sensors and components fitted to your car. TPMS control module N88 location.
Xentry will be able to diagnose the actual cause of your fault codes, but don't overlook the wiring between N88 and the antennae. Or the fact that the wheels may have been swapped out with the originals/or no longer have the original sensors fitted.
Incidentally, to answer your original question, Semi Active Roll Stabilisation has absolutely zero to do with suspension control. I suggest that something was lost in translation from the German for 'intermittent rolling radius monitoring'
I don't know what your deal is, but I never asked for any assistance in diagnosing the tire pressure monitoring system.
You've also contradicted yourself several times throughout this thread and presented a lot of incorrect information causing nothing more than confusion.
This may be my third time asking you to stop. You are not helping anyone here or anyone who may see this in the future.
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