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Discussion Starter #21
all 4 of mine are clean and dry. I'm under the impression that a bad accelrometer will give a fault code. When tested with an auto logic, there are no faults present in my system. (and again when you measure at the wiring at the individual shocks, there is power at each corner's harness, so wiring, switch and edc module seem to be good).

Autologic can force the fronts to go into soft mode, but the rears do not respond.
 

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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.
x2!

My tech was working some stuff at the back and accidentically, barely dissconected one of the rear RH plugs of the EDC and when I took it for a spin I noticed it was whole lot more firm, no matter what position was my EDC switch, both will be solid green and no message of level suspension or any suspension fault in my cluster. Can't remember if I plugged my OEM BMW Modic scanner to read out codes and/or if were present, but I remember my tech was repairing something at the back so I told him check the connecotrs of the damper and he found one barely dissconected....that fixed the firm ride.

Somehow, from that experience came to my mind to add an auxiliary switch in my cockpit to have a extra setting of EDC, super sport mode by disable the communciation to one damperhiha Never did it though.
 

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Discussion Starter #25
I'll have to check again, but i've got solid wiring, getting a signal at each edc dampener, but still the rears do not change (even though it's getting a signal thru the wiring harness). Could be something simple, i've checked it but doesnt hurt to check again.
 

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Mottati I have the same problem. Did you solve it? All wiring checks out but scanner can't change rears out of 'hard'. Dealer says shocks must be faulty but I can't get my head around what internal fault could cause this across both shocks.
 

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Discussion Starter #27
i replaced my dash switch and all works now.
 

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Well I'm grateful to know that but I must say it's increased my confusion! I thought the switch (not fitted to my car) just stopped the system switching into 'soft' mode. I wonder how that could cause the rears only to stick in 'hard'? Did anyone explain?
 

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Discussion Starter #29
no good explanation. In "P" mode my switch would occasionally not light up, and after checking everything else, i figured i'd try a new switch. Plugged it in, p mode lights up consistently now and the rear feels normal. I have not tested it with auto logic or any other scan tool, but there are no fault codes stored and i can certainly feel the difference between S and P modes.
 

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Well I'm grateful to know that but I must say it's increased my confusion! I thought the switch (not fitted to my car) just stopped the system switching into 'soft' mode. I wonder how that could cause the rears only to stick in 'hard'? Did anyone explain?
I thought my rears were stuck in firm, then changed the accumulators (after years) and now have blissful comfort.

I wonder whether there is some interaction - high pressure causing valve sticking, or something.
 

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no good explanation. In "P" mode my switch would occasionally not light up, and after checking everything else, i figured i'd try a new switch. Plugged it in, p mode lights up consistently now and the rear feels normal. I have not tested it with auto logic or any other scan tool, but there are no fault codes stored and i can certainly feel the difference between S and P modes.
Well this is the perfect post ^

I have been encountering this odd behavior now for going on two full months and could not track down any faults. After driving the car for at least 15 minutes the light on P would just go out and system would go full firm. Shut the car off and restart and all would be good again for another 10 to 15 minutes.

I'll be swapping in a new switch to see if it solves my problem as well. Thanks for posting... this kind of info is invaluable given the limited numbers of EDC cars still on the road.
 

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Discussion Starter #32
does anyone know what kind of voltage signal comes from the cluster regarding speed to the edc module? Should it be a 5V signal, 12V, variable based on speed? I assume there is a speed where the system switches to firm. My touring is having an issue where i'm not getting a consistent speed signal. This is also causing my cruise control to not work, and the obc avg speed and fuel econ are not getting a signal. I'm wondering what kind of signal should be coming out of the cluster to the edc module.
 

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I believe that the EDC plus system receives the speed signal from the front nearside ABS sensor via the ABS control unit and not from the cluster. The signal is described as square wave 0-12v. However I have struggled to find any totally reliable / uncontested information on the working of EDC so I won't be surprised if someone now contradicts me!
 

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GDA - this sounds like my previous problem with the EDC. Are you getting an error message when the EDC switches to firm? The camber sensor has a built-in delay so that it doesn't 'overreact' to the camber briefly going out of spec. I believe the delay is 8 minutes rather than 10-15 but close enough? So maybe your car is overloaded or the sensor is playing up. Mine was cured by changing the sensor and a plug in the sensor wiring.
 

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Discussion Starter #35
I believe that the EDC plus system receives the speed signal from the front nearside ABS sensor via the ABS control unit and not from the cluster. The signal is described as square wave 0-12v. However I have struggled to find any totally reliable / uncontested information on the working of EDC so I won't be surprised if someone now contradicts me!
this is interesting. Based on the wiring schematics, it comes from the cluster, black wire, white stripe. Good to know about the square wave pattern. I have the car at a local bmw shop addressing a gearbox and diff leak and they're a bit baffled by the edc system.
 

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I have an ever-growing list of garages who are baffled by the EDC. My local BMW main dealer currently heads the list having told me this week that they couldnt work on my car as it has "aftermarket" shocks. What do you mean, says I. Your shocks are made by Boge says them! I nearly spilt my complimentary coffee.
 

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GDA - this sounds like my previous problem with the EDC. Are you getting an error message when the EDC switches to firm? The camber sensor has a built-in delay so that it doesn't 'overreact' to the camber briefly going out of spec. I believe the delay is 8 minutes rather than 10-15 but close enough? So maybe your car is overloaded or the sensor is playing up. Mine was cured by changing the sensor and a plug in the sensor wiring.
I have only received the EDC Not Active error twice. All the other times it just defaults to firm and other than that switch light going out, its just as if I had selected S mode.
 

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I have only received the EDC Not Active error twice. All the other times it just defaults to firm and other than that switch light going out, its just as if I had selected S mode.
Not exactly,
When EDC Sport mode is selected the medium solenoid is selected/energized.
The firm shock mode is only engaged by the EDC controller with no solenoids being selected/energized.
The firm shock mode is normally only available momentarily with high EDC accelerometer rates and during system failure where the firm mode is constant because no solenoids are selected/energized.
 

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A number of sources say that selecting S just has the effect of taking the soft solenoid out of the equation so that the system only switches the medium solenoid - giving the two states of medium solenoid open: MEDIUM or medium solenoid closed: HARD depending on input from the sensors. But I've also come to realise that all EDC is not the same as there have been versions - mine says EDC PLUS on the ECU - and maybe model year variations (mine built June '92) so please excuse any misinformation!
 
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