EDC and Servotronic stopped working

[Helmsman]

Originally Posted by JoeM3SSII

Helmsman, how many miles do you have on your tires ? The reason i ask is that new tires thread gives additional cushion but tires with more wear (or tires with uneven wear) may increase road feel. I wonder if that may make it more difficult to detect the difference between edc comfort and sport. just a thought.

what is very perplexing is the servo. why would that also not work anymore with no error codes. I cannot find an answer.

Hi Joe, got Michelin PSS new last Spring, half and a bit in them. Nope, this is not about the tires, the suspension is stuck in Sport.

[Helmsman]

Originally Posted by Mike Benvo

You can switch to another EDC module. As long as it's from the same variant E9x, it should work fine. The software is the same across all the platforms, there are variations in coding depending on options and style.

Not sure what you mean by EDC is programmed through the ECU... All body modules are programmed via OBD and go through the junction box. The "part number" can refer to the software version.

Thanks Ben, then I know it works should I need to go that route.

[Rajmun340]

Originally Posted by Mike Benvo

Prog ECU old/new simply refers to the software version it had before programming and the software version flashed to it afterward.

Yes I have, and it appeared to work fine. I programmed it a week or so afterward.

What is DEM?

that's great to know, thanks Mike.

DEM is a word slip sorry, I meant DME of course. DEM is an acronym I've often used before at work for Dynamic Elements Matching

[Rajmun340]

Originally Posted by Helmsman

Hi Joe, got Michelin PSS new last Spring, half and a bit in them. Nope, this is not about the tires, the suspension is stuck in Sport.

Ok then an EDC-K module swap would quickly tell us if the module is the issue. In the positive, that would prove that bmw's self-diagnosis software does not have functionality coverage/feedback on the EDC driver analog side.

In the negative then we really need to probe the current signals flowing into the solenoids with the special adapter cable. This can only be done with the ISTA tool Testplan. I have been pushing my dealer to try this, but it seems it exceeds their level of expertise or they're not willing to try anything on a car without error codes.

[BPMSport]

Originally Posted by JoeM3SSII

Ok then an EDC-K module swap would quickly tell us if the module is the issue. In the positive, that would prove that bmw's self-diagnosis software does not have functionality coverage/feedback on the EDC driver analog side.

In the negative then we really need to probe the current signals flowing into the solenoids with the special adapter cable. This can only be done with the ISTA tool Testplan. I have been pushing my dealer to try this, but it seems it exceeds their level of expertise or they're not willing to try anything on a car without error codes.

That's why the test plans are there... So any tech fresh out of UTI is suddenly an expert

If following a test plan is beyond their abilities, I'm concerned that this might not be the best place to have this diagnosed...

[Helmsman]

Originally Posted by Mike Benvo

That's why the test plans are there... So any tech fresh out of UTI is suddenly an expert

If following a test plan is beyond their abilities, I'm concerned that this might not be the best place to have this diagnosed...

Mike, the frustration here is that the dealer/BMWs test capability apparently doesn't cover the in fact issue we have going. No fault code = no issue, while the friggin dampers are stuck, on low milieage mint cars...
Would you by any chance have any additional knowledge or experience that I could feed into my discussions with the dealer mate? For now the next action is to measure the signals on the damper connector, something they didn't judge worth doing during the first run €200 diagnos...

[Rajmun340]

Originally Posted by Helmsman

Mike, the frustration here is that the dealer/BMWs test capability apparently doesn't cover the in fact issue we have going. No fault code = no issue, while the friggin dampers are stuck, on low milieage mint cars...
Would you by any chance have any additional knowledge or experience that I could feed into my discussions with the dealer mate? For now the next action is to measure the signals on the damper connector, something they didn't judge worth doing during the first run €200 diagnos...

Same here, the foreman had my car for half a week and did nothing beyond OBD re-programming. If there is no code they feel exempt to do anything more.

The reason i am not fixing it myself is I don't have the time nor access to the minimum car connectivity software tools required for the job. Compared to the engineering expertise I do in my own work, diagnosing the EDC module is a joke. Which makes it the more frustrating for me to have to rely on mildly incompetent BMW people for fixing my car.

[Helmsman]

Mike, Joe, picked up an EDC module from another ZCP today. Received input from a fellow M3 guy that it should be a straight swap regardless of different VIN, but the DSC would need to be coded. Would you by any chance know what this mean? Both car and module are ZCP. Aiming to give it a try tomorrow.

Thanks

[Rajmun340]

Originally Posted by Helmsman

Mike, Joe, picked up an EDC module from another ZCP today. Received input from a fellow M3 guy that it should be a straight swap regardless of different VIN, but the DSC would need to be coded. Would you by any chance know what this mean? Both car and module are ZCP. Aiming to give it a try tomorrow.

Thanks

Helmsman, Here is what i know. There is an "individual data" memory for edc, it holds shocks mileage but i think that does not matter. My edc was reprogrammed without resetting that info. Also My edc module was reprogrammed without reprogramming the DSC, i have listings proof of that. I would say just swap it, it should work right away and hopefully we can narrow down the problem.

cheers

[Helmsman]

Joe as I know you're waiting; Didnt get around to do it and now heading out for a week. Have my appointment with the dealer first thing when back so will take it from there.
Was also hesitant when I red about the mileage compensation potentially stored in the module as the car I got it from had just over 100k miles on the clock. I'll get back after the dealer visit.

Cheers

[Rajmun340]

Originally Posted by Helmsman

Joe as I know you're waiting; Didnt get around to do it and now heading out for a week. Have my appointment with the dealer first thing when back so will take it from there.
Was also hesitant when I red about the mileage compensation potentially stored in the module as the car I got it from had just over 100k miles on the clock. I'll get back after the dealer visit.

Cheers

Helmsman, you would not loose any memory in your original EDC module if you disconnect it. Just like a cell phone keeps saved phone numbers and other informations if you take out the battery even for years. All electronics have a secondary button cell battery for sustaining static and flash memory which only requires an infinitesimal small amount of current (femto ampers). When you reconnect the primary battery everything is the same.

The edc module that you are swapping in will have different values but that does not matter for the purpose of doing a testdrive on an issue were you are trying to distinguish between not working at all and working edc modes. Even though the shocks riding age differ from the 100k miles car it came from, you should still be able to tell it's working or not.

I would swap another edc module in a heartbeat if only there was someone local to lend me theirs. unfortunately nobody stepped forward. It's quite a rare car in this state.

[Rajmun340]

Helmsman, this may help. just some info on how to remove the trims to access the edc module.
Cheers

[Helmsman]

Yep I've been down to the module Joe, easy enough. But again should the module work - which I'd guess it would - I know myself I'd be wondering about the previous car' mileage impact and not be completely happy.
Now should BMW not be able to move forward when I see them beginning next month, a swap will be relevant in order to continue my own investigation.

[Rajmun340]

Originally Posted by Helmsman

Yep I've been down to the module Joe, easy enough. But again should the module work - which I'd guess it would - I know myself I'd be wondering about the previous car' mileage impact and not be completely happy.
Now should BMW not be able to move forward when I see them beginning next month, a swap will be relevant in order to continue my own investigation.

Helmsman, I understand. But don't forget, Mike said he swapped an edc module and did not reprogram it for a week and it worked right away. That takes out the guesswork if a swap will work.
I think that that previous 100k miles car shocks may have developed some normal fade from shock oil degradation and shock piston ring sealing wear (but probably very minimal depending on the roads, etc). Worst case if I assume that that car's shocks damping effect is noticeably less than a low mileage shock, its edc would have compensated by offsetting the setting for the solenoid control to 'harder'. By doing a 'hot swap' of that edc module into your car, edc modes will come back to life if the module was the issue. The impact of the older shocks edc settings on your car might be a faintly harder ride across the range (from comfort to sport) but nothing comparable to our issue of edc modes not working. Then if you planned to keep the older car edc module a resetting of its memory would be on order. However In the case the modes stayed dead even with the swapped module, you could revert to your original module and be back to square one. Since that damper memory is in the edc module itself, not the main ECU, your original module would still be intact as it was.

Sorry for the long paragraph. hopefully it is only a matter of time until we get to the bottom of those issues with this M3. After we have technical proof of the fault (even without a fix) then should the dealer persist in disingenuously evading fixing the issue(s) under pretext of 'no error code read' , BMW NA will surely redress them. They have been playing dead with me, not attempting to fix the issue. With a stronger case to present, I will make sure BMW NA gets full account of how they handled the whole situation too.

[BPMSport]

I can reset the adaptation values remotely.. I've also seen EDC modules malfunction because of a stored offset value, not sure where it comes from but have been able to reset that also to restore functionality.

[Helmsman]

Originally Posted by Mike Benvo

I can reset the adaptation values remotely.. I've also seen EDC modules malfunction because of a stored offset value, not sure where it comes from but have been able to reset that also to restore functionality.

Thanks Mike, good to know.

[Helmsman]

Joe,

back from the dealer. They reprogrammed the EDC (and the rest as well as they can't select modules). Thought for a moment it made a difference but that was only wish thinking.
Talking to them again they however claim they felt a difference and start hesitate taking further action, like in your case.
While the tech admitt he doesnt get the opportunity to drive the E9x EDC very often (we only have like 450 E9xM' all together in the country) he still suggest he knows the car Ive been driving daily since 2.5y better. On top charging for investigations that hasnt led to anything start to anoy me, as well as making me nervous. This is my baby, consuming significant investment!

Pushing for another slot shortly to get the damper signals measured, for which they now say they possibly dont have an appropriate adapter.

Cheers

[Rajmun340]

Helmsman, thanks for the update. sorry to see you've reached the same stage with your dealer as mine and they did the same reprogramming.

I am a bit ahead of you on a few things but still haven't solved the issues.

With the car turned off, after unplugging both the front struts connectors i've measured the front solenoids resistance for continuity, got 2.2 ohms on both. Fine. With a voltmeter i also measured the signals coming from the edc. Got 0.409 V on the front left and 0.015 V on the front right. This is actually normal as both solenoids on the same axle are serially connected with power feeding to the FL, the center node most likely weakly pulled down to ground when off by the edc module and the FR returning to ground (it's a pwm drive output stage i won't go into details).

This does not prove the edc is working in normal operation (i don't have adapter to test with car turned on and dealer is ignoring me plainly) but no obvious electrical faults were found.
This lead me to a second theory. A faulty but not failed speed sensor. This could offset the edc algorithm computations without triggering any error codes.

Also i have a weird drivetrain noise which i'm wondering could be a faulty wheel bearing. forum threads indicate there have been factory defective batches of rear wheel bearings failing at very low mileage (several 2012 cars). There is more to it. Our wheel bearings have an internal magnetic disc that generates a square wave when read by the speed sensor. Forum archive showed that when the speed sensor fails (usually with error codes though) the wheel bearing had to be changed too.

Then i remembered that servo steering maps are speed dependent too. This may be the common link i have been searching for with both edc and servo modes not functionning. All this is still highly hypothetical.

One thing is not hypothetical and that is the dealer foreman knows little about these cars and they're trained by bmw so they don't do any thinking outside what the diagnostic tools tells them. Their diagnostic is based on error codes and they never assume one second that this system has holes. We know it does, but they're in denial and they're escaping their warranty responsibility.

Cheers

[Helmsman]

Thanks for the inputs Joe. The two of us trying to figure this system out is becoming redicilous, in addition Im chatting with a M3 member who are employed as tech by Volvo. Still this gives more understanding and ideas about how to make progress than talking to BMWs dealer...

Out of curiousity; also red earlier that the both solenoids on the same axel are controlled equally. Obviously doesnt make sense as the system is supposed to controll the 4 courners individually. Opening the EDC box I bought there is however only two output stages from what I can judge i.e two power transistrors and drivers. Doesnt matter for our problem but puzzled me.

Like my dealer tech tested my car with a colleage and concluded my EDC works I did the same today going out with a friend driving. Just to clear possible brain ghosts really. He immediately recognised there is no differences between the damper settings.

Will shase my dealer up tomorrow and bloody demand them measuring the signal. Joe, any idea about whether it could provide signal while stand still just to stop when start driving ie after receiving input from the accellerator and steering sensor. (I assume they can only measure standing still if at all)

Cheers

[Rajmun340]

The more people the better. I've also chatted with Malek who knows the m3 suspensions hands on inside out. His recommendation is to change both front wheel speed sensors and bearings on my car. But since i'm under warranty, my first problem is to get the dealer to recognize the issues.

4 MOSFETs would be the minimum to control each corner individually with PWM currents drivers. If only 2 MOSFETs in the module each wheel is not independent. The third party pdf symbolic wiring diagram on page 5 i posted earlier( E60 M5 , same system) shows the FR solenoid terminal is in series with the FL , this forces same current through both (same on the rear). The sensing is done from 4 independent wheel speed sensors but the command distributes identical currents left and right per axle.
All of this isn't even complicated but we have no schematics.

I know what you mean about clearing brain ghosts caused by dealer. They did the same with me. But my memory speaks, I know the difference, it no longer works. There is not one time when it used to work that I could not feel the transition between modes.

If we believe that 3rd party pdf then the solenoids current control stops below 3mph. But there has to be some software test mode to override this for testing. Otherwise one possibility is a dyno. Another is to use a scope with memory option probing the voltage directly at the edc module terminals in the trunk, but given how resourceless dealer is..

An edc module swap test would tell us the most in the easiest way.

cheers.

[redpriest]

What a nightmare. How much would it cost you out of pocket if you weren't able to convince them to do it under warranty?

[Helmsman]

Originally Posted by redpriest

What a nightmare. How much would it cost you out of pocket if you weren't able to convince them to do it under warranty?

God knows as nobody knows exactly what the issue is. More of a challenge at this point is to get our dear dealers to get an interest in tracking down root cause and solving the issue. Being "M certified" technicians it puzzels me why that isn't the case, should be a nice break of the usual routine work!