Solving EDC deterioration?

[Helmsman]

Originally Posted by Brandoch

https://www.bimmerpost.com/forums/sh...php?p=21370133 vertical dynamics file.

It explains EDC K (Which is what we have)

Thanks mate. This document is what I had parts of (believe given by a dealer earlier on). Good stuff.

Btw it also confirms the compensation for aging...

"Tolerance Adaptation
The damper force is diminished as part of the operating time function. Diminishing damper forces are compensated by current (amperage) reductions which are calculated by the tolerance control. This also individually compensates for mechanical damper wear on each axle."

...as well as reset/clearing adaptations:

"Notes on Service
Mechanical wear causes the dampers to weaken over the service life, therefore a running time memory adapts the damper curves towards a harder setting (over time). Faulty dampers must be replaced together (in pairs) on a single axle. After a replacement, the running time memory for the front or rear axle must be reset with the BMW diagnostic equipment"

Interestingly it speaks only about function over time rather than mileage. I would have thought mileage/driving have a greater impact than potentially parking over long time, good to know.

[M3SQRD]

Originally Posted by Helmsman

Thanks mate. This document is what I had parts of (believe given by a dealer earlier on). Good stuff.

Btw it also confirms the compensation for aging...

"Tolerance Adaptation
The damper force is diminished as part of the operating time function. Diminishing damper forces are compensated by current (amperage) reductions which are calculated by the tolerance control. This also individually compensates for mechanical damper wear on each axle."

...as well as reset/clearing adaptations:

"Notes on Service
Mechanical wear causes the dampers to weaken over the service life, therefore a running time memory adapts the damper curves towards a harder setting (over time). Faulty dampers must be replaced together (in pairs) on a single axle. After a replacement, the running time memory for the front or rear axle must be reset with the BMW diagnostic equipment"

Interestingly it speaks only about function over time rather than mileage. I would have thought mileage/driving have a greater impact than potentially parking over long time, good to know.

It is odd that they only mention time but it does agree with what you’ve experienced with your 10+ year old, ~25k mile car which is now much harsher than it was originally. At a minimum, the low-frequency accelerometer response (i.e., chassis/sprung mass motion in the ~1-2 Hz range with a low-pass filter) could be used to estimate the number of damper cycles by counting the number of accelerometer sign changes. This wouldn’t capture cycles from the motion of unsprung mass (i.e., up/down motion of wheels/tires, brakes, hub/knuckle, etc. mass) but it’s better than nothing. The edc control strategy is in the frequency domain so the data already exists.

[Helmsman]

Originally Posted by M3SQRD

It is odd that they only mention time but it does agree with what you’ve experienced with your 10+ year old, ~25k mile car which is now much harsher than it was originally. At a minimum, the low-frequency accelerometer response (i.e., chassis/sprung mass motion in the ~1-2 Hz range with a low-pass filter) could be used to estimate the number of damper cycles by counting the number of accelerometer sign changes. This wouldn’t capture cycles from the motion of unsprung mass (i.e., up/down motion of wheels/tires, brakes, hub/knuckle, etc. mass) but it’s better than nothing. The edc control strategy is in the frequency domain so the data already exists.

Well not a 25k car these days but coming closer to 60k miles, during 13 years.

Yes there are interesting data referred to, if it only was possible to capture.... As mentioned I haven't seen any EDC "live data" on the couple of tools I happen to have. Also what I can see of BMWs own diagnose intructions/possibilities indicates there aren't much data being possible to accesse? There is a tool mentioned in the end for measuring on the EDC module, assumingly when it is taken out. Other than that damper needs to come out and be put in test bench?

[M3SQRD]

Originally Posted by Helmsman

Well not a 25k car these days but coming closer to 60k miles, during 13 years.

Yes there are interesting data referred to, if it only was possible to capture.... As mentioned I haven't seen any EDC "live data" on the couple of tools I happen to have. Also what I can see of BMWs own diagnose intructions/possibilities indicates there aren't much data being possible to accesse? There is a tool mentioned in the end for measuring on the EDC module, assumingly when it is taken out. Other than that damper needs to come out and be put in test bench?

I wasn’t talking about data we may have access to. I was referring to what BMW has access to. Three of the four dampers have accelerometers mounted on them and their response is used to control pitch and roll of the chassis. BMW could have used the accelerometer response data to account for “cycle” degradation in addition to “age” degradation.

[Helmsman]

Originally Posted by M3SQRD

I wasn’t talking about data we may have access to. I was referring to what BMW has access to. Three of the four dampers have accelerometers mounted on them and their response is used to control pitch and roll of the chassis. BMW could have used the accelerometer response data to account for “cycle” degradation in addition to “age” degradation.

Ah, got you. Yep guess they could, but they don't seem to have done.

[RocketyMan]

Originally Posted by Brandoch

https://www.bimmerpost.com/forums/sh...php?p=21370133 vertical dynamics file.

It explains EDC K (Which is what we have)

Awesome! Give this guy a "like." This is the exact literature needed.

Looks like the solenoid controls the valving of these dampers rather than through a fluid.

M3SQRD
So a couple of take-aways from the technical training regarding "age" and adaption reset:

[RocketyMan]

Originally Posted by M3SQRD

BMW’s EDC is mechanical and uses a twin-tube damper. Forum member Racer20 is a chassis engineer and he develops and tunes these systems for a living. The first link below is his comparison of F8x EDC vs. F10 M5 EDC vs. Cadillac ATS 3.6 MR. The second is his comparison of ZCP and base EDC dampers at max and min damping. He clearly states in a thread (which I have not found yet) that BMW EDC is mechanical, not MR. He also goes on to say MR systems perform poorly in cold temperatures as well as discussions further limitations with MR. I’ll keep looking but below are the two links I’ve found so far.

EDC Damper Review
https://f80.bimmerpost.com/forums/sh....php?t=1005377

F8x ZCP EDC dampers vs. Base EDC Dampers
https://f80.bimmerpost.com/forums/sh....php?t=1525983

Great point. Makes 100% sense about the shortfalls of MR based systems.

[M3SQRD]

Originally Posted by RocketyMan

Awesome! Give this guy a "like." This is the exact literature needed.

Looks like the solenoid controls the valving of these dampers rather than through a fluid.

M3SQRD
So a couple of take-aways from the technical training regarding "age" and adaption reset:

Yes. I read thru the document.

[Helmsman]

Originally Posted by RocketyMan

Looks like the solenoid controls the valving of these dampers rather than through a fluid.

The fluid is controlled by a solenoid controlled valve.

[M3SQRD]

Originally Posted by RocketyMan

Great point. Makes 100% sense about the shortfalls of MR based systems.

I’m the one to blame. I specifically asked him if there was coding that had to be done when replacing edc dampers. I kept emphasizing “coding required” in all of my communication with him. I’d like to thank you and Helmsman again for setting me straight on the incorrect use of coding. I asked him if BMW required any test plans and/or procedures to be executed when replacing an edc damper. He said there was. Also, he has a copy of the vehicle dynamics document linked above as well as other training documents related to edc. So it was my continued incorrect use of coding that was the problem.

[kimiraikkonen]

Originally Posted by Helmsman

Btw quick feedback on this since I got Bimmergeeks Protool: shows the same thing, e.g. "Normal" doesnt show. So clearly not Protool thing then but the way the signal is being picked up by the tool.

Helmsman. Picking up on an older thread on EDC settings (Comfort/Normal/Sport) showing up different in ISTA. Where are you tapping into on the EDC voltage measurements you are doing in your videos?

I want to replicate to verify that at least I'm getting a voltage difference between settings.

To recap for others, when I test my EDC in ISTA (and even other scan tools), I see the following:

• Comfort Setting --> shows up as "Comfort" in ISTA
• Normal Setting --> shows up as "Sport" in ISTA
• Sport Setting --> shows up as "Comfort" in ISTA

Thx!

[M3SQRD]

Originally Posted by kimiraikkonen

Helmsman. Picking up on an older thread on EDC settings (Comfort/Normal/Sport) showing up different in ISTA. Where are you tapping into on the EDC voltage measurements you are doing in your videos?

I want to replicate to verify that at least I'm getting a voltage difference between settings.

To recap for others, when I test my EDC in ISTA (and even other scan tools), I see the following:

• Comfort Setting --> shows up as "Comfort" in ISTA
• Normal Setting --> shows up as "Sport" in ISTA
• Sport Setting --> shows up as "Comfort" in ISTA

Thx!

Do you notice a difference in damping/ride quality between the two “Comfort” settings? Has this been reported by other members?

[Helmsman]

Originally Posted by kimiraikkonen

Helmsman. Picking up on an older thread on EDC settings (Comfort/Normal/Sport) showing up different in ISTA. Where are you tapping into on the EDC voltage measurements you are doing in your videos?

I want to replicate to verify that at least I'm getting a voltage difference between settings.

To recap for others, when I test my EDC in ISTA (and even other scan tools), I see the following:

• Comfort Setting --> shows up as "Comfort" in ISTA
• Normal Setting --> shows up as "Sport" in ISTA
• Sport Setting --> shows up as "Comfort" in ISTA

Thx!

Hey man, I connect an amp meter on one of the shocks connectors (i.e. unplug and hook up s meter in between). Long wires into the right windor, done. Back when I did plug into all four shocks where the rear ones obviously are more tricky to access.
I did a new measure the other week, the fact that Protool and apparently ISTA doesn't show a difference is some other error but it doesn't affect that actual setting/current change.

Let me know if more questions comes up!

Edit: earlier thread with some further details:
https://www.m3post.com/forums/showthread.php?t=1646115
Cheers

Ps. Finally with new battery in place I plan to reach out to Bimmergeeks to get them to implement the EDC adaptation reset, which curently isn't there but Bimmers confirm the function is available. They need a car to add the feature so I'll plan to volonteer remotely. (tad strange that they don't have a chunk of mates/cars closer around in order to develop their product).