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Discussion Starter #1
Since buying my 3.8 a few weeks ago, i've felt that the suspension always felt firm, regardless of switch position. Yesterday i had my friends at Performance Technic plug in their autologic system to look for faults. No faults found, but my suspicion was correct. Despite the switch position, the shocks are set on firm. The autologic does see when i change the switch from program to sport, so i believe the switch is good. Also, the autologic can switch the shocks from firm to soft. You can hear the shocks "click" and when you bounce a corner, it's notably softer. But it seems the system doesn't respond to the switch.

This makes me suspect the EDC computer is faulty? I have no stored faults, No EDC inactive on the dash display and the switch on the dash seems to work fine.

Any tips or advice? Not sure if i can get a new edc computer, will check on Monday. Finding a good used one in the US is likely impossible with about 40-50 3.8's in the US. What do you with edc experience think?
 

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Is there any record of the rear accumulators being changed? My 3.8 is riding really hard and a bit high in the rear this spring, and I'm working on changing out the rear accumulators now. When they fail, you lose all rear dampening essentially, so the ride gets very harsh. Are your accumulators original?
 

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Discussion Starter #5
I've got a good/know working edc module on its way. Not sure on the accumulators at least the hoses look new-ish. I think the issue is electrical, since the autologic shows the dampening set to firm regardless of switch position. We'll see in a few days.
 

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My problem was traced back to a duff EDC ECU also. In my case, the switch didnt light up green, it simply flashed green when turning on the ignition. What does yours do ?

It could also be a sensor (but that would be expected to log a fault I think), or the infamous rear wiring harness issue (which has been known to cause EDC issues with no logged fault).

Let us know what happens.
 

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Discussion Starter #8
Thanks Matt. My switch doesn't blink. Solid green when on the S mode, but the P mode does not light up at all. Previous owner assumed the bulb was burnt out in the P side of the switch. Now I assume P doesn't light up because of a fault. I looked at the harness last night where it enters the body, it is nicely wrapped, looks like it's been repaired in the past, so if the edc module doesn't do the trick that'll be where i look next.
 

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I had the exact same issue, many many years ago now.
It was the rear harness wiring.
It threw no codes or obc warnings.

Just constantly had firm dampers.

Some of the loom wires were chaffed & shorted.
I'm guessing this locked the dampers to firm.

Worth pulling the loom down for an inspection.
It makes a good opportunity to wax oil all the SLS pipework at the same time !

Regards,

Alan.
 

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Discussion Starter #10
Alan I was looking at the harness from below. Would you say it's best to disconnect from the edc module and pull the harness out from under the car? There was an area that did look like it had seen repair in the past, electrical tape covering the harness where it entered the bulkhead. Probably should look there.
 

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Hi,

I didn"t do it that way.
I raised & supported the rear of the car, then carefully unclipped the harness from the plastic retainers on the vehicle floor.
I didn't touch the edc plug, but did pull the firewall boot out.
I needed to unplug the SLS level sensor & diff speed sensor to do this, but that gave me enough slack to
Unfold the harness out from where it is squeezed by the rear subframe.

If you search my photo gallery there are a couple of shots of the harness there.

Regards,

Alan.
 

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Discussion Starter #12
Thought i would update this thread, but no fix yet. My 'known good' edc module made no difference. I started investigating the wiring, and found the rear harness had been repaired previously. Then a 'garage renovation/expansion' project took over at my house, so some of the cars were shipped out for temporary storage.
Here's what my shop tells me about this car's edc:

No faults in edc found with autologic, fronts will switch from soft to firm. Input from switch is fine. Rear shocks will not respond to auto logic. Signals are coming from edc module, to front and rear (edc module good, as is switch). Signals are getting to the rear shocks when switched, but shocks are not switching. This leads them to believe the rear shocks are bad, either electrically or mechanically, so they've defaulted to stiff.

Of course from other threads, we know one of the rear edc units is NLA.

I may consider taking the rear shocks out and tinkering with them over winter, but any thoughts on this? I suppose for the cost of a couple of EDC shocks (if i could even get them) i could go with a KW coil over kit.....
 

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S!

Related to EDC so chiming in here if you do not mind. I finally got the EDC system to work(new front absorbers and an assortment of other parts), as far as the light on the switch indicates this and no error messages are coming to Check Control. The car feels softer with P and more responsive on S. I had to replace the front most sensor and the EDC control box. I just wonder if it is working as it should as the original box had text "EDC Plus" on it and this new one I installed has EDC IV(from a E34 540i 6-speed with EDC package). Still the system seemed to fire up just fine. Or am I wrong?
 

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I guess you are aware that the EDC-system locks itself into default-modus 'S' when the dampers have gone bad.
There are presently various activities going on to establish what the EDC damper supply situation with BMW in fact is,
trying to convince BMW that there is a demand in order for them to allow BOGE/SACHS to do a new production run.
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Meanwhile there is a new alternative for an EDC damper restauration offered by a workshop in Poland
(which in fact is even being referred to by BMW staff).
 

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M5Touring reg. Sounds good if there are restoration services for these dampers. I have an extra set of rear EDC shock absorbers and it would be great to refurbish them and keep as reserve. Got any more info on this, web site or similar?
 

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S!

M5Touring reg. Sounds good if there are restoration services for these dampers. I have an extra set of rear EDC shock absorbers and it would be great to refurbish them and keep as reserve. Got any more info on this, web site or similar?

I'll keep an eye on this thread too...
thanks for the info Karl ! :byebye:

PS: rear EDC dampers here in france seems to be still available but: 1350€ for one and ex VAT !!:eek7::eek7::crying:
I will ask my contact...
 

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Discussion Starter #17
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I guess you are aware that the EDC-system locks itself into default-modus 'S' when the dampers have gone bad.
There are presently various activities going on to establish what the EDC damper supply situation with BMW in fact is,
trying to convince BMW that there is a demand in order for them to allow BOGE/SACHS to do a new production run.
-
Meanwhile there is a new alternative for an EDC damper restauration offered by a workshop in Poland
(which in fact is even being referred to by BMW staff).
Yes, i do know the S mode is the fail safe default. And i am aware of the EDC supply thread. I'm unsure, at this point, that i'd send my dampeners to poland for repair, until i've heard of other's experiences. (I do wonder why, if BMW is recommending this facility, they just do not offer an exchange service for these, to keep parts in the supply chain).
 

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When mine are swapped out this week, save for the Left Rear, I am going to work on finding a local tech to work out a refurb. Sending worn shocks from the US just seems ridiculous considering the fab shops around here that can refurb hydraulics for back hoe and design custom air bag systems for 64 Bonnevilles on the same work bench.
 

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Discussion Starter #19 (Edited)
Sending worn shocks from the US just seems ridiculous considering the fab shops around here that can refurb hydraulics for back hoe and design custom air bag systems for 64 Bonnevilles on the same work bench.
I agree, there shouldn't be anything magical about edc dampeners that they can't be overhauled by a more local hydraulic facility.

what is more aggravating is not knowing if one, or both of my rears are bad. Is there a way to isolate this? If the bad one is still available, i'd obviously order it now.
 

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What about your acceleration sensor? They will force the S position if they burn up. Mostly, if the EDC are dry, they are presumed to be functioning unless there is an electrical issue
RR Wet = Bad

LF Dry = Good


I'll post up pics of the refurbed SLS and all the new piping next week. But I did have my green light go out and pulled codes and found a bad sensor which I replaced with a used one and it came back alive.
 
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