R129 1991 500SL

[Keith R129]

Not sure about ADS but ABC pumps lockout when they detect a pressure loss on the outlet. To get them to pump again you need to pressurise the reservoir to around 6psi. When I had to do mine I made up a cap using an old wine cork trimmed to fit the didstick hole with a needle type inflator hooked to a bicycle pump.

Do I need the bleed valve open to do that or will it just come back in to the reservoir?

 

[LostKiwi]

When I did my ABC pump I had the system sealed. The purpose of pressurising the reservoir is to prime the pump without it detecting fluid pressure loss.

 

[Keith R129]

When I did my ABC pump I had the system sealed. The purpose of pressurising the reservoir is to prime the pump without it detecting fluid pressure loss.

I'll go and find a cork and give it a try, I'll let you know what happenrs. Many thanks.

 

[Richard Moakes]

The ADS1 pump is a very simple vane pump and has no back pressure detection.

If there is no outlet flow from the pump, then I would be looking for an inlet blockage or ultimately removing the tandem pump and rebuilding it.

Richard


Sent from my iPad using Tapatalk

 

[LostKiwi]

The ADS1 pump is a very simple vane pump and has no back pressure detection.

If there is no outlet flow from the pump, then I would be looking for an inlet blockage or ultimately removing the tandem pump and rebuilding it.

Richard


Sent from my iPad using Tapatalk

Good to know for future - thanks for the info.
Seems much simpler than ABC!!!

 

[McDonald]

Everything is simpler than ABC

 

[LostKiwi]

Everything is simpler than ABC

Must remember that next time someone says "It's as easy as ABC..."

 

[Jan Stribrny]

Hello all, I have been searching through this forum and actually did not find a clue for my ADS issue. But I did learn a lot here.

In September 2018 I bought 1994 SL320 in great shape and condition. I realized that car has ADS which works not. Rising the car is not working and the car is very stiff even for my tires (18" BBS RSII rims with 245/40 on front and 275/35 on rear). From search, I realized that ADS, when not works, is in the firmest setup (both solenoids in damping valves off).
All other behaviour is fine - ADS warning light in a dashboard is lit after ignition and goes off after starting. I tried function of a hydraulic fluid level indicator by sucking out hydraulic fluid and it lit the dashboard warning light. Both switches for rising level and soft/firm suspension are lit when switched on and goes off when switched off. But without any effect...

Levelling is working fine. See video of front axle where the car sits quite low when not driven.

Now after I changed all four pressure accumulators, the vehicle is not sitting low on the front as on video and ride is slightly better but not as it should be. I have no chance to drive vehicle with working ADS but my mechanic had when he worked at MB dealership in 90'. But I can describe how it behaves. If there is a big pothole or speed bump then it really filters the bump. When there is a series of small bumps on road then I feel a vibration through all the vehicle (coming more from front to my senses). And switching soft/firm button makes no difference.

I did check fault codes with the following results (no warning lamp has been lit since I bought the vehicle):

ADS
13 Oil level switch (ADS) - Was that recorded after my trial with sucking the fluid?
14 Steering angle sensor not activated/initialized - Might that be after the previous owner changed the battery (it is quite new) and did not perform full lock movement to both sides?

ABS
30 CAN data line to electronic accelerator/cruise control/idle speed control module

EA
3 Right EA/CC/ISC actuator (left cylinder bank) (M16/1)
14 Closed throttle position contact switch

BM
11 Voltage supply for accessory equipment control module interrupted
12 Voltage supply for ABS control module, ABS/ASR control module or ASD control module interrupted

To me, it looks like mechanics and hydraulics are OK (levelling is fine) but electronics is not switching the damping valves to softer settings.

I think engine harness was already changed. The solenoid for valve timing was oily so I cleaned space around. To do so I disconnected the connector from the solenoid and I realised that there is a second wire with an identical connector that is just tied there and not connected. Can harness be from V engine with two solenoids? Might that be in connection with an error of EA 3 Right EA/CC/ISC actuator (left cylinder bank) (M16/1)?

I did erase both codes in ADS and re-check them for appearance. These did not appear again. But there is snow and I cannot drive the car now, so I just started it in a garage for 2 mins.

Any thoughs where to look first? And how? Can any of the above mentioned fault codes indicate what is wrong?
Should I erase all codes and check if they appear after cranking up the engine?

Thanks for all remarks.

jan

 

[LostKiwi]

Yes erase all codes. @Richard Moakes is your man for ADS.

 

[Jan Stribrny]

Hello all, finally snow is gone, so I can drive a car.
All fault codes were erased prior drive. After charging battery ADS lamp was lit until I did lock to lock movement with the steering wheel. Then it went away. Again I erased the fault code for that. Then I drove approx. 60km. I checked for any fault code to appear. Nothing was there.
My thoughts are the following.
All the electronics are fine otherwise I would see fault codes?
If so that means N51 is sending proper signals to damping valves? Might be possible that all 4 are faulty? Not likely.
How to check the output of N51 towards Y51-54? To unplug the connector of one valve and measure the voltage coming to it? Will that be possible done on a standing vehicle - I mean is standing vehicle in other than most firm setting?
Or better use clamp multimeter on connected wire?
If the voltage is not coming means that N51 is faulty? How that can be checked?

Thanks for any further ideas.

jan

 

[Jan Stribrny]

Hello all, I do have some new info.
I did send my ADS ECU to a German company who checked it and says it is OK.
I hardwired my damping valves' solenoids to 12V directly. Well, not completely directly but to headlights fuse and rear light bulb and through additional fuses just to be safe. So I can switch the damper valves by switching lights on and vice versa.
Yes, the car rides now much smoother over bad pavement. It is not adaptive, off-course, but I can live with it.
Now I want to create box which will sit in place of ADS ECU with relay operated by ADS Sport model switch from the center console. That way I can use original wiring and control. I am wondering if the same can be done for lifting car up and lowering it. But I am missing electrical schematics for that in ADS I.
If anyone has an interest in how to do what I have done, feel free to ask.

jan

 

[LostKiwi]

Hello all, I do have some new info.
I did send my ADS ECU to a German company who checked it and says it is OK.
I hardwired my damping valves' solenoids to 12V directly. Well, not completely directly but to headlights fuse and rear light bulb and through additional fuses just to be safe. So I can switch the damper valves by switching lights on and vice versa.
Yes, the car rides now much smoother over bad pavement. It is not adaptive, off-course, but I can live with it.
Now I want to create box which will sit in place of ADS ECU with relay operated by ADS Sport model switch from the center console. That way I can use original wiring and control. I am wondering if the same can be done for lifting car up and lowering it. But I am missing electrical schematics for that in ADS I.
If anyone has an interest in how to do what I have done, feel free to ask.

jan

These might help:

 

[Jan Stribrny]

These might help:

Thanks, LostKiwi, I do have all the materials you've posted. The issue is that you can find in the testing procedures on how to test button S77 for increasing the level of a vehicle. But in electric schematics, there is S77 not present. But maybe it is enough to double-check the signals mentioned in the test procedure and find the pins are correct.

 

[Chrisu77]

Hi everyone,

I’m just changing the leaking O-rings to my ADS-1 block but the damn barrel shaped part fell out from the block and I haven’t find any picture which way it should be in the block. It goes both ways in but the other end has small piece cut off, so there has to be the correct direction.

 

[Jan Stribrny]

Hi everyone,

I’m just changing the leaking O-rings to my ADS-1 block but the damn barrel shaped part fell out from the block and I haven’t find any picture which way it should be in the block. It goes both ways in but the other end has small piece cut off, so there has to be the correct direction.

Hello Chrisu77, I don't see your picture. Which barrel shaped part you mean? Y36 - solenoid for lifting?

 

[Chrisu77]

It was the part number 50 in the upper picture. Bypass valve. Find out that it should be the cutted edge downwards when the valve is installed in the car.

Now the car is back together without leaks.

 

[Jan Stribrny]

Hello all, I do have some new info.
I did send my ADS ECU to a German company who checked it and says it is OK.
I hardwired my damping valves' solenoids to 12V directly. Well, not completely directly but to headlights fuse and rear light bulb and through additional fuses just to be safe. So I can switch the damper valves by switching lights on and vice versa.
Yes, the car rides now much smoother over bad pavement. It is not adaptive, off-course, but I can live with it.
Now I want to create box which will sit in place of ADS ECU with relay operated by ADS Sport model switch from the center console. That way I can use original wiring and control. I am wondering if the same can be done for lifting car up and lowering it. But I am missing electrical schematics for that in ADS I.
If anyone has an interest in how to do what I have done, feel free to ask.

jan

Hello all, after long time. If somebody is interested I put a web page dedicated to my progress on ADS overhaul. Maybe someone would find it helpful.

R129 ADS

R129, ADS, adaptive damping system, Mercedes-Benz, SL

r129ads.freevar.com

jan