could someone scope the EDC signal going to the dampers???

[marconi118]

I am trying to drive the E92M3 EDC dampers without all the control modules and sensors. This because I have a non EDC car, and too much work-expensive to retrofit the whole system.

Basically the EDC dampers have an internal valve that without any electric signal applied to it is closed and the damper is full hard.

When appliyng 6V to the damper the valve is open and the samper is fully soft.

To obtain the different setting (confort, sport, super sport...) the EDC control module sends a PWM signal (like the one that controls a wastegate for example)
In this way the valve is not fully open all the time, and leads to a mid stiff damper, depending on the duty cycle of the signal.

To avoid damaging the EDC damper, it needs to receive the PWM signal at the right frequency (Hz). this is the only thing I DON't know.

So if a member with an EDC car, and some electronic knowledge, could hook an oscilloscope or a frequency counter to any of the whires going to the dampers and measure the frequency of the signal???

The easiest way is to intercept the signal in the connector on the front damper, located on the strut plastic cap under the hood (if fits in the alu strut brace reinforcement)

This would be very cool and helpful for all of us.

Once I know the Hz, I will post here a simple circuit, to drive the dampers and change the damping by a simple turn knob in the cabin, from soft to hard.

[slicer]

Why on earth are you doing this? The EDC dampers are not worth the trouble IMO.

[marconi118]

I have to stay with OEM dampers for legal reasons in my country

no KW JRZ etc....

so my best bet is EDC dampers and a manual control of the damping via this PWM controller I plan to build.

Need only the frequency of the signal, then everything done

[Denk]

Hey, I once worked for Marconi, probably no relation, anyway...man, I'd just stick with your non edc suspension, it's a pretty nice raw setup.

[marconi118]

EDC E93 dampers (that I already purchased) are stiffer than the non edc e92 dmpers.

they match well with eibach springs, the ride is less bouncier than with the e92 dampers.

I have already the EDC dampers in my car, and wires to the dash. need only to set the frequency in my driver and enjoy variable damping for little money

[marconi118]

bump

[8k3]

wont this be a variable signal? I don't think it's a specific freq the entire time

[marconi118]

it a fixed frequency, only the duticycle (on tyme versus off time) changes.

It it the same type of signal that is used fro wastegate control, but the frequency maybe different?

[marconi118]

bump

[marconi118]

bump

[Johnfr]

Perhaps when the authorities pull you over, in your country, to check and see that you have OEM or NON OEM EDC they could tell you... since they must "routinely" check non OEM from OEM EDC damping functionality- certainly they have test equipment to make sure nobody is operating anything other than OEM EDC equipment. By the way, what is the fine for operating non-OEM EDC ?

[marconi118]

Still hoping someone could help me

[kenwelch]

Originally Posted by marconi118

Still hoping someone could help me

From the E65 EDC-K technical manual:

Power Supply
Low current supply to the damper valves results in hard damping and a high current results in soft damping. The EDC-K control module determines the setpoints and outputs pulsewidth modulated (PWM) signals to the damper valves to regulate the current flow. Current flow limitation is ensured by an overcurrent detection and deactivation. All of the analog inputs are protected by diodes against positive and negative overvoltage.

The following analog signals are processed by the EDC-K control module:
• Vehicle supply voltage
• EDC-K switched output voltage
• Damper valve voltage and current

External voltage supply fault fluctuation (nominal should be 5 V +/- 10%)
Voltage supply to EDC control module between 2 V and 8 V

Valve Activation/Output Stage Circuit
The solenoid valves have low resistance, approximately 2.2 ohms per valve at room temperature because high current is needed at a low voltage. The current is set in the 0 to 2 Amps range depending on the desired damping force. The setpoint value will not exceed 2 Amps to avoid valve damage. The solenoid valves are connected in series for each axle and are supplied with a ground (PWM for continuous adjustment) from the EDC-K control module.

[coloradoe92m3]

Don't get this at all

[4corners]

Can we increase the voltage to make them stiffer? We have three settings. Why not a dial?

[1MOREMOD]

Originally Posted by 4corners

Can we increase the voltage to make them stiffer? We have three settings. Why not a dial?

I think that is his plan to make them adjustable over a wider range. Full mush mode busted cadillac to rigid.

[M3PO]

Originally Posted by 4corners

Can we increase the voltage to make them stiffer? We have three settings. Why not a dial?

It sounds like you risk valve damage if you supply them more than 2 amps so I'm not sure that would be a good idea.

[kenwelch]

Originally Posted by M3PO

It sounds like you risk valve damage if you supply them more than 2 amps so I'm not sure that would be a good idea.

Agree
More voltage = more ampere flow = lighter wallet. Don't do it!
When there is no supplied voltage they are at max control (stiffness).

[marconi118]

I will send a PWM signal to the dampers directly to vary the current form 0A completely hard, to 2A completely soft.

the only missing piece information I couldn't find in the pdfs is the frequency in Hz (should be between 100 and 1000 hz) of the PWM signal.


If someone wants do do it on a non EDC equipped M3, remember you have to wire the dampers in series and then you can feed them with 12V, this gives aprox 2A of current setting them to the max soft.


I will have one regulating knob for front and one for rear to independently go from full soft to hard....

[donovane92]

Originally Posted by marconi118

I will send a PWM signal to the dampers directly to vary the current form 0A completely hard, to 2A completely soft.

the only missing piece information I couldn't find in the pdfs is the frequency in Hz (should be between 100 and 1000 hz) of the PWM signal.


If someone wants do do it on a non EDC equipped M3, remember you have to wire the dampers in series and then you can feed them with 12V, this gives aprox 2A of current setting them to the max soft.


I will have one regulating knob for front and one for rear to independently go from full soft to hard....

I am retrofitting EDC to a non-m, and I daily a e92 m3 with EDC. I recorded an oscilloscope reading of the signal to rear EDC dampeners using snap-on VERUS 4 channel lab scope. I did not acquire a signal with a uniform wave form, and I am unsure if control is done through PWM. My observations:
No light on switch: 5.7 V
One light on switch: 7.4 V
two lights on switch: 11.1 V

I only picked up a signal in Volts DC. Other settings I tried without success were specific to Pulse Width, Duty Cycle, Frequency, Volts AC RMS.
Could it be that I'm reading the Vrms value and this is actually PWM? If this is the case, would I be okay to send DC 6V to the shock for a softer ride?

[marconi118]

you absolutely need to limit the current to 2A to avoid blowing the shocks