BMW M5 Forum and M6 Forums banner

1 - 12 of 12 Posts

·
Registered
Joined
·
497 Posts
Discussion Starter #1
Hi there gents,

I'm planning to do a live test (test while driving) to check out all the sensor input and solenoid output of the EDC module.
Here's what I'm planning to do:
1) Remove the back seat.
2) unmout the edc module and disconnect the plugs, open the box and reconnect the plugs.
3) fire up the old lady and bring a friend with a voltage measuring device and ofcourse pen and paper.
4) Don't drive but engine is running. First measure all the input and output (The speedo input from the ECU is digital so that won't work). The other signals are analogue I believe (Vertical and horizontal accelo devices and potentiometers from steering column
5) Start driving at 50 km/h on relatively bumpy road and measure all the input and output pins directly on the EDC module (careful not to make a short circuit:))
6) Head for the highway and start with 120 km/h and measure again
7) Head for a highway intersection where you can continuously drive soem higher speed turns and do the measurements
8) Go back home and process all the data and post it to the forum

I know this is not very scientific but at least it's something


Any tips from the techies outhere:wroom:hiha
 

·
Registered
Joined
·
19 Posts
crash and burn:
i have some experience collecting and sorting data from large marine diesel applications.
not the same but...

define parameter speed/road conditions vs sensor current in vs solenoid current out
record enough data to have some accuracy remove outliers plot curve.
how quickly you can read and record data will be crucial as this is a call/answer type of logic.

do you intend to determine if a fault exists?
or are you naturally curious?

I am too simple to know much more than this. On my project a mathematician was required to sort the data into useful pieces but we were measuring every second for 24 hours.
john
 

·
Registered
Joined
·
497 Posts
Discussion Starter #3
Mostly curious but I want to make sure the solenoids respond the way they should. Obviously I've got NO reference to validate the collected data. The inputs are there continuously and the module combines those inputs and then "decides" what solenoids to activate or not. So ot's gonna be difficult:)
 

·
Registered
Joined
·
750 Posts
Much easier is to view the parameters and actuators in a live data diagnostic program. I believe I can view them with the software I have. I shall verify it in the evening when I am @ the garage.

If you want to measure it don't use a silly voltmeter but an osciloscope. Its possible these sensor/actuators respond fast. A regular voltmeter won't be that fast to show it on the screen, a scope does.
 

·
Registered
Joined
·
497 Posts
Discussion Starter #5
@Tomba, I don't have an Osciloscope unfortunatly. How do you simulate the vertical and horizontal acceleration then? And if the module "says" power on to a solenoid. How do you knw the solenoid is actually moving in the shock letting the damper oil pass through?

Cheers
 

·
Registered
Joined
·
750 Posts
@Tomba, I don't have an Osciloscope unfortunatly. How do you simulate the vertical and horizontal acceleration then? Cheers
Not, reading the values while driving lets you see if they (acceleration sensors) are still working. If you look at the schematics you will see the (solenoids) left/right rear is grounded by the same pins, left and right front are also connected that way. So it is only possible to setup different front en rear damping settings.


And if the module "says" power on to a solenoid. How do you knw the solenoid is actually moving in the shock letting the damper oil pass through?

Cheers
By pushing it or driving it while activated. I am sure you will notice the difference between comfort and sport position. Putting the car on a shock demper test setup would result in different readings. Or by viewing the osciloscope while measuring the appropriate pin. I suspect they are activated by different PWM %. At least, I can not see any feedback signals from the solenoids so its hard to say if it is possible to "see" if they are moving. Either the solenoid is broken (measuring resistance and current during operation) or a internal leakage has occured.


Try to measure it, if you can not come out of it you can always pop by to read out the ECU at our garage.
 

·
Registered
Joined
·
497 Posts
Discussion Starter #7
Thx tomba, i will measure the resistance of the solenoids from the edc pins. I will try and do the tests while driving. I thought only the speed from the ecu was a pulse and rest analogue signals. I would already be glad to see voltage changes on the input pins. That would give at least the assurance that the sensors are doing something.
The strange thing is however that i dont feel amy difference in sports or comfort. In general it feels really sturdy and hard but that could be the black powerflexes on the suspension as well.

Keep you posted

Sent from android using tapatalk:):)
 

·
Registered
Joined
·
1,298 Posts
i dont feel amy difference in sports or comfort. In general it feels really sturdy and hard but that could be the black powerflexes on the suspension as well.
The only time the edc system on my car behaved as you've described above was when there was a wiring fault
in the rear loom.

There were no EDC INACTIVE warnings, just very very solid shocks.

Others have had this same issue over time...if an accelerometer or steering ring was at fault
the system would usually display "INACTIVE".

It's quite straightforward to check the rear harness.

Just thought I would mention it.
(The rear harness has been know to rub on the rear subframe
and short wires...)

Regards,


Alan.
 

·
Registered
Joined
·
497 Posts
Discussion Starter #9
I know about the wireloom. Had a look at it but didn't unwrap it to check wirebreaks or shorts. Will have to I think. The other option is the check every wire with a voltage meter and deduct from the result whether there is a short or break and in which wire.

Keep you posted.

Willem
 

·
Registered
Joined
·
7,667 Posts
Doesn't the system default to the firm setting if there is a control unit fault or a medium solenoid valve circuit failure ?

I don't believe there would be any visible warnings if this were the case .

D
 

·
Registered
Joined
·
497 Posts
Discussion Starter #12
@tomba....not yet. First fix is a coolant hose:) that's easy. maybe this weekend if I can find the spare time. Girlfriend doesn't like me driving holding a voltage meter:) Hav to do it with a friend so I can drive and make some nice highway turns:)
 
1 - 12 of 12 Posts
Top