EDC and Servotronic stopped working

[Helmsman]

Originally Posted by JoeM3SSII

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.

Joe, for your curiosity below are the EDC module inside. Quite some time since I was even close to analogue design so you're guesses are better here. In my view looks like an ASIC chip doing the control while there are two output stages?

Btw, the reason I don't want to try this module just yet are not only the adaption values but to be honest nervous should something go wrong, probably won't increase the dealer activity.

[Sunny D]

I would like to add my car to this as I am having the same issue. Mine started by getting an EDC error and code. As I am out of warranty (but still only 25k miles on the car), I took it to a local Indy shop and they found the EDC module was toast. They installed a new one, coded it, and now it seems stuck in Sport and is super stiff all the time.

I too are not sure what to do at this point. I do have the old module if someone wants to try it.

[Helmsman]

Originally Posted by Sunny D

I would like to add my car to this as I am having the same issue. Mine started by getting an EDC error and code. As I am out of warranty (but still only 25k miles on the car), I took it to a local Indy shop and they found the EDC module was toast. They installed a new one, coded it, and now it seems stuck in Sport and is super stiff all the time.

I too are not sure what to do at this point. I do have the old module if someone wants to try it.

Sorry to hear Sunny. And what does the dealer say about it being stuck in sport, denial?

[Rajmun340]

Originally Posted by Helmsman

Joe, for your curiosity below are the EDC module inside. Quite some time since I was even close to analogue design so you're guesses are better here. In my view looks like an ASIC chip doing the control while there are two output stages?

Btw, the reason I don't want to try this module just yet are not only the adaption values but to be honest nervous should something go wrong, probably won't increase the dealer activity.

yep, only 2 Power MOSFETs on the board attached to the chassis for thermal dissipation.
That 128 pin microprocessor looks vulnerable being on the same board with a 4 MHz 2 A switched PWM driver.

The big electrolytic caps are the first thing you can visually check. If the top of any of them is not perfectly flat, with a bump, the cap is gasing out and has started to fail.

[Rajmun340]

Originally Posted by Sunny D

I would like to add my car to this as I am having the same issue. Mine started by getting an EDC error and code. As I am out of warranty (but still only 25k miles on the car), I took it to a local Indy shop and they found the EDC module was toast. They installed a new one, coded it, and now it seems stuck in Sport and is super stiff all the time.

I too are not sure what to do at this point. I do have the old module if someone wants to try it.

If you have a voltmeter with car turned off could you disconnect the plugs on the front L and R struts and measure 1) the impedance into the strut 2) the voltage that arrive to the plug. At least you'll know if a solenoid has failed open.

[Helmsman]

Originally Posted by JoeM3SSII

If you have a voltmeter with car turned off could you disconnect the plugs on the front L and R struts and measure 1) the impedance into the strut 2) the voltage that arrive to the plug. At least you'll know if a solenoid has failed open.

I'd assume the EDC would generate a code at least if a damper broke!?

[Rajmun340]

Originally Posted by Helmsman

I'd assume the EDC would generate a code at least if a damper broke!?

It depends. but most likely not with a shock edc valve fault. The pwm driver can only monitor current flowing through each axle solenoids in series usually with a current sense amplifer at the PWM output stage. If either solenoids faults into open circuit, that would be detected. But if the valves gets stuck and no longer change the flow of oil in the shocks for edc the solenoids would still have the same current flowing and edc would not detect it.

The edc is also getting vertical acceleration data from each wheel. But that is certainly not used to diagnose anything less than a fully broken damper. So it's an open loop command after the solenoids.

The issue we are having is already telling me this system is not properly designed for comprehensive "in-use" self diagnosis.

[Helmsman]

Joe, Im waiting for my dealer to receive further guidance from BMW. Next meeting I expect will be with him and the dealership mgmt. God knows when though.
You, when do you expect mentioned expert to turn up?

[davesaddiction]

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.

Hey Mike, I've apparently got a bad EDC control unit (failed at the same time as my steering angle sensor - which has been replaced - you and your guys helped me get my tune reapplied). Would your recommendation be to just find a used one and swap it in and see if it works? How important is it to get one from the same variant M3 - E90/E92/E93?

Thanks,
Dave

[davesaddiction]

All - just found and purchased a used EDC control unit off of an '08 sedan (like mine). Will swap it in when it arrives and report back.

[Helmsman]

Originally Posted by davesaddiction

All - just found and purchased a used EDC control unit off of an '08 sedan (like mine). Will swap it in when it arrives and report back.

Interesting Dave. You have failure codes or just stopped working like mine?

[davesaddiction]

Originally Posted by Helmsman

Interesting Dave. You have failure codes or just stopped working like mine?

I do have the codes. I'm not sure how it might be related, but I got an alignment a while back (not from the dealer...) just before a driving trip to the Ozarks and right afterward I had several codes related to the steering angle sensor. A few days after that, I got the EDC code, too. They were all intermittent for a while, and then came on consistently. I found a DIY about the crystals that can form on the steering angle sensor, so I got up the nerve to pull off the air bag and the steering wheel to see if that was my issue. No luck, sensor wheel looked pristine... Finally took the car in and paid the $$$ to get the steering angle replaced and recoded, which took care of all the codes but the EDC. I've been driving it for a while like this - didn't want to pay the $$$ again at the dealer, but finally got fed up with the harsh ride on the rough streets around town. I've also got a trip to Austin coming up - Lone Star Le Mans! - so I wanted to get it sorted before then.

Thankfully I found this thread with the encouraging words from Mike and the instructions for how to get to the unit.

The EDC control unit I found is off an E90 like mine from the same year, and I would assume similar miles, but no idea. Bought for $95 from Ebay - definitely worth a shot at that price!

Dave

[Helmsman]

Originally Posted by davesaddiction

I do have the codes. I'm not sure how it might be related, but I got an alignment a while back (not from the dealer...) just before a driving trip to the Ozarks and right afterward I had several codes related to the steering angle sensor. A few days after that, I got the EDC code, too. They were all intermittent for a while, and then came on consistently. I found a DIY about the crystals that can form on the steering angle sensor, so I got up the nerve to pull off the air bag and the steering wheel to see if that was my issue. No luck, sensor wheel looked pristine... Finally took the car in and paid the $$$ to get the steering angle replaced and recoded, which took care of all the codes but the EDC. I've been driving it for a while like this - didn't want to pay the $$$ again at the dealer, but finally got fed up with the harsh ride on the rough streets around town. I've also got a trip to Austin coming up - Lone Star Le Mans! - so I wanted to get it sorted before then.

Thankfully I found this thread with the encouraging words from Mike and the instructions for how to get to the unit.

The EDC control unit I found is off an E90 like mine from the same year, and I would assume similar miles, but no idea. Bought for $95 from Ebay - definitely worth a shot at that price!

Dave

Cheers Dave. Also bought a module but haven't dare put it in. Should something go wrong in the middle of negotiations with the dealer. Car has only 29k miles and insured so will not give up pushing the dealer just yet. Will be very interesting to receive your feedback though.

[BPMSport]

Originally Posted by davesaddiction

Hey Mike, I've apparently got a bad EDC control unit (failed at the same time as my steering angle sensor - which has been replaced - you and your guys helped me get my tune reapplied). Would your recommendation be to just find a used one and swap it in and see if it works? How important is it to get one from the same variant M3 - E90/E92/E93?

Thanks,
Dave

You should get one from the same variant so the coding data matches the chassis, or get any of them and have it reprogrammed.

[davesaddiction]

[delete]

[davesaddiction]

Originally Posted by Mike Benvo

You should get one from the same variant so the coding data matches the chassis, or get any of them and have it reprogrammed.

Thanks for the reply - I've ordered one off an '08 sedan, just like mine, so I should be good!

[Sunny D]

Hopefully someone can make the swap this weekend to see if it solves the issue.

Alex at Alpine was cool to take a look at the coding on mine, all was well, but the date on the module is 2008! It was brand new from a dealer, even got the box. Maybe that could be the issue with mine? My car is a 2011 with ZCP.

[Helmsman]

Originally Posted by Sunny D

Hopefully someone can make the swap this weekend to see if it solves the issue.

Alex at Alpine was cool to take a look at the coding on mine, all was well, but the date on the module is 2008! It was brand new from a dealer, even got the box. Maybe that could be the issue with mine? My car is a 2011 with ZCP.

WTF, so it is changed once already?

[davesaddiction]

Originally Posted by Sunny D

Hopefully someone can make the swap this weekend to see if it solves the issue.

Alex at Alpine was cool to take a look at the coding on mine, all was well, but the date on the module is 2008! It was brand new from a dealer, even got the box. Maybe that could be the issue with mine? My car is a 2011 with ZCP.

Do you have the part number off the box for your "new" one? I guess the earlier version is 37156785193 and the later version is 37156788790. Just trying to confirm that there's no real difference between the two, other than the part #. I was getting one from an '08, but apparently that one sold, so now I'm getting one from an '11 with the -8790 number.

If the -5193 worked in your car, the later version should work in mine.

[Helmsman]

Originally Posted by davesaddiction

Do you have the part number off the box for your "new" one? I guess the earlier version is 37156785193 and the later version is 37156788790. Just trying to confirm that there's no real difference between the two, other than the part #. I was getting one from an '08, but apparently that one sold, so now I'm getting one from an '11 with the -8790 number.

If the -5193 worked in your car, the later version should work in mine.

Dave, just to double confirm, the box I bought was from a 2011 ZCP, with the 8790-1 part no.

Cheers

[davesaddiction]

ECS's site says nothing about this part being model year specific. https://www.ecstuning.com/b-genuine-...t/37156788790/

Hopefully I'll have it in a week and can report back.

[Helmsman]

Originally Posted by davesaddiction

ECS's site says nothing about this part being model year specific. https://www.ecstuning.com/b-genuine-...t/37156788790/

Hopefully I'll have it in a week and can report back.

I don't know where the ZCP specific SW is stored but if in the actual EDC module I assume that would be a reason to have different part numbers.