[arklatexV12]

So, I'd thought something might be odd about my ADS, and I was right! I hooked up STAR and I see that I am getting no comfort mode.

But, there are no faults in the system (didn't even clear it)c and I can't find anything wrong with sensor readings, switches, electrical voltage, etc.

The regular diagnostic module I cleared after figuring this out (it had a few engine codes). No luck.

...anyone got ideas?

 

[arklatexV12]

Keep in mind, it had been fixed several months ago and functioned perfectly up until recently.

 

[thisisntchris87]

I've been dealing with this same "problem" for quite sometime. I have problem in quotes because some days I feel like it's working and other times I don't, which makes me believe that there may actually be nothing wrong with my ADS and it's just that I'm expecting more out of the system than what it's designed. It honestly makes me just say it's "working" and I leave it at that, but it's a constant itch I can't get rid of.

I've toyed around with every menu item on my SDS that I can find and not gotten anything resolved. I have been wanting to run a full check of all the sensors using the readouts from my SDS, I just haven't gotten around to it. I've also wanted to buy a new module off eBay, but again I've not gotten around to it. Last I looked at the actual values and compared it with vales I found in the ADS test docs, everything is fine!

If you do manual actuation on your dampeners and bounce the car on the four corners then you know at least the dampening valves work and you can compare between soft and firm modes to see for yourself.

I'm sure you're aware of the differences of ADS 1 and 2 and the years those versions were around.

What makes you think your SDS is telling you that you aren't getting comfort mode?

 

[thisisntchris87]

Keep in mind, it had been fixed several months ago and functioned perfectly up until recently.

Intriguing. If you really are noticing a difference then it's decent confirmation that the system can get stuck in firm mode without a code.

How's your battery voltage when you start the car? Are your accumulators fairly new? I'm sure your s600 is in good condition, but you gotta start somewhere.

 

[arklatexV12]

I actually had the accumulators replaced, OEM, less than a year ago - so that isn't it. Pretty certain based on bouncing it, both manually actuating it via STAR and trying to put it in comfort mode normally (engine on).

 

[thisisntchris87]

Covering more of the basics. Since you have a 95 model, ADS 2 can remember the last setting you used for the suspension which is stored in memory even after restarting the engine. Have you switched back to comfort mode so that the car will start in that mode?

I wish I had a more definitive answer, but this system gets annoyingly opaque when it has this problem. I've even tried removing the module, letting it sit on the kitchen counter for a while, and plugging it back in to see if it did anything, but no joy.

 

[arklatexV12]

Yes, I've turned it off in either setting. It doesn't seem to affect it other than what mode it starts in, or rather what mode the sport LED light is on.

 

[arklatexV12]

Mostly because I hadn't realized it had stopped working, and I use it often so I've definitely turned it on/off in either mode recently.

 

[thisisntchris87]

Try checking to make sure your battery stays above 10.5 volts when cranking. I've read that if the voltage dips below that, it'll kick ADS into firm only mode.

 

[arklatexV12]

I have a new battery and alternator, first things I had to replace when I got it....but I will take a look. Big battery too.

 

[arklatexV12]

Removed the ADS computer, started the car, turned it off, replaced ADS computer (hoping to reset it). No change.

 

[thisisntchris87]

Alright few questions, just to narrow stuff down.

What did you fix with your ADS a few months ago?

When you got it fixed did you bounce the car with your hands when the car was running and notice that it was softer? If you bounce it today with the car running, is it the same? For the dampeners to soften the ride, they need to be energized (basically, voltage opens them) so the car ideally needs to be running.

You haven't been doing work with a hammer on the car anywhere near the accelerometers have you?


Following the diagnostic manuals, in a case of no DTCs but the complaint is still reported it says to run the hydraulic test and the electrical tests. Hydraulic test involves playing with the leveling valve to check that the vehicle raises as the struts fill with oil. Electrical test involves looking at voltages coming to and from the sensors and module using special equipment. Something I think you and I both have already done using our SDS kits. I haven't bounced the car or spun my wheels like it says to do for ADS 1, but it's something I've been wanting to do.

I'm rambling sorry!

Fact is, this particular issue requires some deep diagnosis.

 

[arklatexV12]

Alright few questions, just to narrow stuff down.

What did you fix with your ADS a few months ago?

The first thing I had replaced was the accumulators. In about.....May, I had the steering angle sensor replaced. OEM Benz. That was when the system started functioning correctly - it could still so previously only if I didn't turn the steering wheel. In July I replaced a body acceleration sensor that was intermittently at fault (it had a code for it).

When you got it fixed did you bounce the car with your hands when the car was running and notice that it was softer? If you bounce it today with the car running, is it the same? For the dampeners to soften the ride, they need to be energized (basically, voltage opens them) so the car ideally needs to be running.

Yes, I only test with it running. I can still do it today using the STAR system via manually actuating each corner (making it go soft mode) and tell the difference. When it was fixed, I could do the same thing - I even demonstrated it at a few meetings in a local club I'm part of (the normal way, not manually with STAR).

You haven't been doing work with a hammer on the car anywhere near the accelerometers have you?

No. Though a recent repair had me replacing things near the passenger side headlight due to some supposed water intrusion? Was never sure that water intrusion actually happened, no signs. There's another BAS around there, isn't there?

Following the diagnostic manuals, in a case of no DTCs but the complaint is still reported it says to run the hydraulic test and the electrical tests. Hydraulic test involves playing with the leveling valve to check that the vehicle raises as the struts fill with oil. Electrical test involves looking at voltages coming to and from the sensors and module using special equipment. Something I think you and I both have already done using our SDS kits. I haven't bounced the car or spun my wheels like it says to do for ADS 1, but it's something I've been wanting to do.

I believe the STAR system does allow me to check those, each was displaying the correct voltage (14.1V car running) and the valves worked correctly when manually actuated (going from <1% firm to ~45-50% on soft).

I'm rambling sorry!

Fact is, this particular issue requires some deep diagnosis.

Please, I really appreciate the help. I have no clue what to do in this situation, your expertise is welcome no matter how long the post.

 

[thisisntchris87]

Your story about demonstrating it to a car club is confirmation for me that ADS can default to firm with no DTCs then.

I've considered it being a silent failure of the computer. However, I find it hard to believe that some little thing in the computer has failed without it either causing a DTC (since there is a DTC for the computer itself) or just failing to communicate with an SDS. Thus I've diagnosed my problems on the assumption that the computer is working fine.

So it might be worth it to check that the sensors are all firmly placed on their mounts. Maybe the computer is thinking something is happening and stiffing appropriately. If it isn't the computer, then it's data going into the computer.

Which brings me to this little observation. On my car while it was idling, my body acceleration sensor (B24) was bouncing between 2.50V and 2.57V while the wheel acceleration sensor was at 2.50V steady, which I thought was weird. I never have though because it was such a small amount of voltage that I figured it wouldn't matter. However, I can't count on such assumptions when the voltage ranges aren't publicly known. Might be something I should look into. Your system on the other hand has three body sensors, but minus the wheel sensor; as long as it's ADS 2.

As for the work on the headlights, the particular accelerometer (B24/3) for the passenger side is closer towards the coffin box. So yes there is one on that side, but not all that close to the headlight.

I Wish I could take my car to Victor from restoreyourmercedes.com. I bet he could fix it.

 

[arklatexV12]

Tried the fluid level - was just above the "MIN" mark, filled it 3/4 of the way to "MAX". Was thinking it could be that fluid level causing it to default firm with no light? No change yet. That was the only thing off for me.....unless parking on an incline matters? I doubt that would cause it to error out.

 

[thisisntchris87]

Only the R129 has any kind of sensor in the hydraulic fluid tank and even if it did there is a DTC for that sensor, so no it wouldn't default to firm. Wish it was that easy!

Parking on an incline shouldn't matter on a technical level. I park mine on a bit of light to moderate incline too, not like that matters since I may have the same issue!

Try checking it anyway! Hook your SDS up to it when you park at some place level and check the sensor readings and see if is different.

The problem in my opinion is either a silent fault of the computer or the computer is being given incorrect sensor data that doesn't cause a DTC, but decides that the car should be firm. Caveat though, I'm not 100% on those being the problem, those are my most likely choices based on my observations and technical knowledge.

 

[arklatexV12]

If we can't get this figured out by the time I go home for Thanksgiving, I'll have my local mechanic take a look at it - he works with a bunch of local W140s (several 600s in particular) and I generally get him to figure out/do things I can't/won't.

 

[thisisntchris87]

I hope he cracks it! I'd really like a hint so that I can possibly get mine fixed too. I don't have mechanics down here that work with w140s!

 

[Silver Benz]

I will tune in t this thread...has my interest as my system is stuck in 'strange' mode!

I updated another thread that my dash shock light is on...but I found no codes with the little LED checker I have. The light on the switch for I guess sport mode still light up when the button is pressed; damned if I can tell a ride difference though. Why the hell is my light on the dash always on!
I have my STAR system enroute; I hope this will give me some insight. I may asking for some help using that software once it shows up since you clearly have experience!!!

Chris

 

[thisisntchris87]

You may end up getting your ADS fixed by whatever you find with the SDS. Ordinarily the ADS computer will force the dampeners to firm if there is a DTC, otherwise the ADS computer actuates the dampeners to open. In both our cases we have no dash light on, but our system is seemingly stuck on firm!