Objective Test of EDC performance

Tommysalami wrote

Tony B wrote

Many thanks!

A bit of reading confirms my second question - can EDC adapt to compensate for wear?

The answer is "yes"...from page 20 of "E65 Driving Dynamics Systems"

Tolerance Adaptation
The damper force is diminished as part of the operating time function. Diminishing damper forces are compensated by current (amperage) reductions which are calculated by the tolerance control. This also individually compensates for mechanical damper wear on each axle.

And from page 23

Mechanical wear causes the dampers to weaken over the service life, therefore a running time memory adapts the damper curves towards a harder setting (over time). Faulty dampers must be replaced together (in pairs) on a single axle. After a replacement, the running time memory for the front or rear axle must be reset with the DISplus.

Other text within the same document confirm the system continuously monitors damper piston speed and adjusts damping force to align to defined maps.

= Closed loop

Acceleration sensors record the driving/road surface conditions and the control module receives the sensor frequency signals for evaluation. The sensor signals are compared with each other for plausibility. The control module logic activates the damper valves according to internal programmed maps to dampen body and wheel movement as needed.


So..."someone" in this thread needs to wind his neck in....

How do you do this? I replaced my rear shocks with Bilstein EDC dampers and feel like it's too stiff, maybe something to do with this

There most likely is a service plan in ISTA to let it know you replaced the shocks. My hunch is there is a service plan similar to registering a battery to reset the charging algorithms.
Edit:
Quick look into TIS has zero reference of resetting anything in diagnostic software when replacing dampers.

derbo wrote

There most likely is a service plan in ISTA to let it know you replaced the shocks. My hunch is there is a service plan similar to registering a battery to reset the charging algorithms.
Edit:
Quick look into TIS has zero reference of resetting anything in diagnostic software when replacing dampers.

Just checked and my scan tool has the option. You can select either the front or rear axle

I think I Just found the service functions for EDC. It says Shock Adjustment, and pre-adjustment. I don't have my M3 with me so I cannot confirm the functions.


Nice Tommysalami !

derbo wrote

I think I Just found the service functions for EDC. It says Shock Adjustment, and pre-adjustment. I don't have my M3 with me so I cannot confirm the functions.


Nice Tommysalami !

Yup, shock adjustment. I reset my rear axle, where I replaced my shocks, so I'll report back in a few days if it feels different. Drove around a little today and couldn't tell if it was a bit softer or just placebo. We'll see for real after this weekend's autocross event.

^ Did you replace with OE or Bilsteins?
Cool discovery, guys!

wyatth wrote

^ Did you replace with OE or Bilsteins?
Cool discovery, guys!

I replaced with Bilstein B6 damptronics in the rears. Had them in the front briefly but didn't like them so kept the OE EDC fronts while waiting on a totally different setup to show up. Prior to resetting, the Bilsteins felt very harsh in the rear, skipping and losing traction over bumps, etc.

So far it does seem to feel more compliant. I reset the front axle too despite being on 90k mile original shocks, and they also don't feel as harsh.

wyatth wrote

^ I reckon factory EDC shocks adjust both compression and rebound, while aftermarket options (eg Bilstein) only adjust rebound. I've also never heard of travel issues unless paired with lowering springs, which is no fault of the dampers.

Yes EDC is relatively primitive and does not transform the car from a Camry to a GT3. But for many people it's still a nice option with noticeable differences in comfort and performance between the modes. Is it the best option, especially for those that track regularly? Absolutely not. But many have it and are happy with it on real world roads. TBD what I do when my ZCP shocks go.

The dampening adjustment is very limited with EDC. Most German cars (BMW included) tend to have high dampening with limited rebound. So what happens is that the initial bump is stiff but then subsequent bumps are soft because the damper has not fully rebounded. This is more comfortable but you don't always have full traction.

With a faster rebound (at the expense of comfort) you get much better road traction and a faster reacting suspension to multiple bumps and rough surfaces. That's why newer systems such as Chervolet's Magride is better. The suspension can be adjusted much faster with electronic signals than physically turning a knob as EDC does.

I ran a few track events with EDC when I purchased the M3. Even on mountain twisty roads, it is way too comfort oriented in any setting. I replaced it ASAP.

bmw>benz wrote

Wrong. Everywhere

Care to explain?

Tommysalami wrote

Just checked and my scan tool has the option. You can select either the front or rear axle

What scan tool are you using? I just checked this with my Foxwell and there's no option to select an axle. Only one option to "Reset Control Unit" under the EDC menu, which I assume is for both axles.

chutak wrote

What scan tool are you using? I just checked this with my Foxwell and there's no option to select an axle. Only one option to "Reset Control Unit" under the EDC menu, which I assume is for both axles.

Foxwell nt510. It was under service/chassis/electronic damping control K.

Z K wrote

The dampening adjustment is very limited with EDC. Most German cars (BMW included) tend to have high dampening with limited rebound. So what happens is that the initial bump is stiff but then subsequent bumps are soft because the damper has not fully rebounded. This is more comfortable but you don't always have full traction.

With a faster rebound (at the expense of comfort) you get much better road traction and a faster reacting suspension to multiple bumps and rough surfaces. That's why newer systems such as Chervolet's Magride is better. The suspension can be adjusted much faster with electronic signals than physically turning a knob as EDC does.

I ran a few track events with EDC when I purchased the M3. Even on mountain twisty roads, it is way too comfort oriented in any setting. I replaced it ASAP.

Physically turning a knob?

Are we talking about the same system?

As for the rest…..you clearly have not read the extracts from the BMW documentation.

Tommysalami wrote

chutak wrote

What scan tool are you using? I just checked this with my Foxwell and there's no option to select an axle. Only one option to "Reset Control Unit" under the EDC menu, which I assume is for both axles.

Foxwell nt510. It was under service/chassis/electronic damping control K.

Thanks, Tommy. Got it taken care of. I have a tendency to go into into the "Diagnosis" menus and totally forgot about the "Service" section.

Replaced all 4 OEM shocks with Bilstein EDC last year, about 9k miles ago. Hopefully I'm not too late for the reset.

Good thread with valuable info. Thanks fellas!

Tony B wrote

Physically turning a knob?

Are we talking about the same system?

As for the rest…..you clearly have not read the extracts from the BMW documentation.

A signal is sent to the shock that turns the dampening up and down. This is a physical shock valve adjustment so it is akin to turning a knob if you did it manually. All the sensors and other stuff just tell the system how to turn said knob. None of the documents provided so far has said otherwise.

Z K wrote

A signal is sent to the shock that turns the dampening up and down. This is a physical shock valve adjustment so it is akin to turning a knob if you did it manually. All the sensors and other stuff just tell the system how to turn said knob. None of the documents provided so far has said otherwise.

And it does not compensate for wear, right….?

Can confirm doing the reset after 90k miles makes the shocks noticeably less harsh. No more hopping and losing traction over small bumps.

Tony B wrote

And it does not compensate for wear, right….?

The wear compensation is a mileage counter that is maintained by the system. It doesn't read wear from the shock itself.

Most likely it turns the dampening higher the higher the mileage until it is reset.

Z K wrote

The wear compensation is a mileage counter that is maintained by the system. It doesn't read wear from the shock itself.

Most likely it turns the dampening higher the higher the mileage until it is reset.

That's exactly what it does. Damper wear is extrapolated as a function over time.

While this doesn't provide any objective test for the original dampers, it does provide context and reason to reset the EDC damper running time memory when the dampers are replaced.

derbo wrote

That's exactly what it does. Damper wear is extrapolated as a function over time.

While this doesn't provide any objective test for the original dampers, it does provide context and reason to reset the EDC damper running time memory when the dampers are replaced.

Yes, I was just going back to the OP's question about an "objective test". As you say, it is not helpful for that.

My point is that EDC is very primitive compared to newer systems on cars. Trying to get a test so he can get new shocks from a dealer? I have no idea how that would work. Short of putting the shocks on a shock dyno and comparing dyno charts to the original specs (something no BMW service center would have), I don't know how that would be compared.

Z K wrote

Yes, I was just going back to the OP's question about an "objective test". As you say, it is not helpful for that.

My point is that EDC is very primitive compared to newer systems on cars. Trying to get a test so he can get new shocks from a dealer? I have no idea how that would work. Short of putting the shocks on a shock dyno and comparing dyno charts to the original specs (something no BMW service center would have), I don't know how that would be compared.

Yeah, I don't know how the dealer would test. I checked all the service functions in the dealership software and could not find such a test. They will most likely only replace if there is a fault and the service plan calls for replacement.

One benefit of this thread was that we found reason to reset the memory timer for each damper axle when replacing a EDC damper.


It's probably as advanced as a normal oil hydrualic suspension can get without getting into magnetic valves/fluid.

I should note that my fronts are still the original 90k-mile EDC shocks and they feel better after resetting. I think in my case the car over-compensated for the estimated amount of wear. They felt great at autocross on the stiffest setting and also are smoother on the street.

Tommysalami wrote

I should note that my fronts are still the original 90k-mile EDC shocks and they feel better after resetting. I think in my case the car over-compensated for the estimated amount of wear. They felt great at autocross on the stiffest setting and also are smoother on the street.

Very nice input Tommy, thanks!

I had no idea wear was compensated for over time, and that this is possible to reset. Been looking into the EDC system now and then since behaviour have changed over the years (less differens between settings).
As mine is daily/calm driven, maybe it has "over compensated" in my case as well. What if it goes too soft after reset, not possiblet to go back I guess?

Only have Carly myself but will check with a mate regarding tool/EDC coverage.

Thanks again,
Nik

Helmsman wrote

Very nice input Tommy, thanks!

I had no idea wear was compensated for over time, and that this is possible to reset. Been looking into the EDC system now and then since behaviour have changed over the years (less differens between settings).
As mine is daily/calm driven, maybe it has "over compensated" in my case as well. What if it goes too soft after reset, not possiblet to go back I guess?

Only have Carly myself but will check with a mate regarding tool/EDC coverage.

Thanks again,
Nik

I am thinking the same.

The differences between the settings seem very small now, so maybe everything has been over-compensated assuming more wear than has actually taken place.