Quick battery voltage drop? Could be your EDC module...

[anom3]

So I posted this a few months back...

http://www.m3post.com/forums/showthread.php?t=1141910

I had a rather quick voltage drop on my M3.

It would drop to like 12.0 within 10-12 hours or so after sitting (locked).

About 1.5 months ago I saw a used EDC module for sale on one of our local ebay like sites. It was 80 bucks. 2013 model, my M3 is 07.07 production. So I ordered it and installed it.

I read a number of threads on here with people having parasitic voltage drain coming from their EDC. That's the main reason I bought it. Plus well, 80 bucks, 20 minute install... I thought hell why not. Dont recall the exact numbers, but the hardware part # was different.

Last night when I parked my vehicle in the garage I landed on the trickle charger cable so I was unable to plug it in for the night.

Woke up this morning and had a look, and the CTEK socket led (I have the socket installed that makes plugging in the CTEK a breeze) was blinking green. Which I believe means 80-100% battery charge. This surprised me as before, it would shine yellow within 6-8 hours.

So I pulled out the voltage meter... After about 16 hours of sitting in the garage... 12.7V.

Thought I would share.

Some caveats, besides the EDC being changed, here is what else has 'changed':

a) The car now sits unlocked over night as I have moved into a free standing home with my own garage. No need to lock it anymore like previously where the car sat in an underground. Maybe this has an effect on the sleep cycle?

b) I have been using ta trickle charger religiously since moving into this new home. So maybe this has 'brought back' the battery some how?

[///M Power-Belgium]

OP's post is very interesting...and after reading his post I thought I am in some way in the same situation and actually most ///M3's do .
It's all about the quick discharging of our battery's..
My story..

After using for years...and charging my battery with my CTEK battery tender I saw that our battery is discharging very quickly !
Because my car is NOT my DD I'm charging my battery over each weekend, so for about 48 hours and let it charge also overnight .
Now from what I noticed...

Last weekend I drove through the Belgian Ardennes and drove about + 250 miles, with lots of high rpm's and high speed braking .
So normaly in a logic situation after all the driving my battery should be charged about 100% full ..
But...

I thought by myself that this would be the ideal situation to check the charge level of my battery , so after 4-5 hours after the long run I plugged my CTEK battery charger on my battery..
And I was shocked of what I saw => The charge/level of my battery was only half full or about 50% down of the max/level ?!?!
So after only 4-5 hours only 50% full , and I thought WTF !

Note: My car is never locked in my garage (because alarm system on my garage) because I know this can drain the battery level as well with the sleep mode of the car ect...
And OP thought that the cause of the discharge was probably caused by the sleep mode when the car was locked , so with this statement the sleep mode is not the cause of discharging our battery because my car is never locked ...
OP said that he replaced his EDC-Module and saw that his battery was keeping the charge level and so I think our EDC-Module is the cause of discharging our battery ..

Strange thing of the whole situation is that OP said he replaced only his EDC-Module , so I think his EDC-Module was still ok , and this fixed the discharge of the battery..
Thanks for sharing .

[Lunker325]

Very good timing on this post, OP I am pretty sure your EDC module is going bad like mine.

I too have been having a parasitic battery drain for the last month or so.

It started as a "increased battery discharge" warning when I would start it up after several hours of sitting. I put a trickle charger on it, but it would never fully charge, so I changed the battery after a week or so of this. I was running a 4 year old battery anyway, so no harm in changing it.
Symptoms went away for a week or so after putting the new battery in, then came back. This continued for a few weeks, increased battery discharge would come up on start up, then sometimes it would not. All of the other symptoms of a low battery were present while the error was occurring, such as comfort access would not work, wonky error codes would pop up on start up as well until the voltage stabilized, then they would disappear.

I got out the multimeter and put it inline with the battery and negative cable, and pulled fuses until the amp draw in sleep mode went to .01. The fuse with the EDC on it was the culprit. This along with a code I pulled "CAN communication failure" of the EDC led me to believe that the EDC module was going bad. Did some more testing with the multimeter and when the EDC module was acting up, it was drawing 1.25 amps when the car was asleep. Pulling the power on the module made it go down to .01, so no doubt the module is going bad.

I did plenty of searching for info on the parasitic power drain and this is the first thread I have seen with the EDC module going bad. Guess I didn't look hard enough!

Currently I have my faulty EDC module unplugged, car is riding very firm, but no more battery discharge errors.

OP, did you have to code the car after installing the new module? Everything I have read says that you do, would like to hear if did, and if the module works in the car without coding it.

[MPowerZ32]

I too had experienced the power drain prior to my EDC module going bad. My car's EDC module has the new part number. I bought a used module with new part number on ebay for $250. I wished I had found the deal OP had for $30! The modules with old part number on ebay were way cheaper. I replaced the module without coding it. All EDC errors went away.

My car is competition package, subjectively i feel the difference in stiffness between comfort (mode 1) and sport (mode 3) is smaller than before. Maybe this is in my head. My understanding is that there is a coding difference between ZCP EDC and regular EDC. Not sure if the module I purchased has the regular EDC logic and needs to be coded. Would like to know if there is way to find out.

[spr]

Please note that the newer EDC module is used on numerous other cars. As such, each program is DIFFERENT. Therefore, if you buy a used or even a new module it must be coded to the proper program for your car just like any ECU.

[jra85]

Yeah definitely wise to highlight this problem on here. This was my experience a couple months ago that I had posted in another thread:

Originally Posted by jra85

My car started doing the Increased Battery Discharge warning late last year, brought it into the dealer, the battery passed testing but since it was 3.5 years old they decided to swap it out under warranty. The car sat in the garage on a battery tender through most of the winter, I started driving it again a couple months ago in the spring, and again started receiving the Increased Battery Discharge warning on the brand new battery. Tried leaving it on the tender, but it must have got to the point where the drain was faster than the rate the tender could charge because the tender never was able to reach the "fully charged" level. A few days later the battery died completely, and the car couldn't even be jumped, so I had to get it towed to the dealer.

At the dealer, they first thought the IBS (Intelligent Battery Sensor) was shorting out, causing a drain, so they swapped it out. I went to pick the car up after this was performed, and at the dealership the Increased Battery Discharge warning appeared! So I left it there for them to keep searching, and they finally concluded the EDC module kept powering on/off while the car was off for some reason, causing battery drain. So they swapped that out too. It's been a few weeks now and at this point the battery tender is able to charge the battery fully, and I haven't had the Increased Battery Discharge again.

Just figured I'd throw that out there if both the battery and alternator are coming back as healthy.

[E92Brembo]

Same here. My battery discharge warnings have disappeared since unplugging my EDC module. The Internet is a wonder tool for things like this.

[Lunker325]

As an update to my situation, I replaced my EDC module with a known working one from member on the board, and everything has returned to normal. No more battery discharge warnings, EDC functions as it should, and no error codes in the module. The unit I got was from a non competition car, so the module calibrations should be the same, thus I did not have it coded to my car.

[code7rpd]

Anyone know the part number for the EDC module?

[E92Brembo]

Mine was bad. Replaced and had codes to remove errors. Solved my battery drain issues.

[///Mobbin]

Just wanted to report that my car developed this exact same issue. At dealer now and they are replacing the EDC module and reprogramming the car. Hopefully I get my ZCP EDC programming back, good reason to do this at the dealer I think. Should be covered by my extended warranty, fingers crossed.

[spr]

Did you buy a new coded zcp etc module? If not they don't take the programming. We tried on 2 modules.

Originally Posted by ///Mobbin

Just wanted to report that my car developed this exact same issue. At dealer now and they are replacing the EDC module and reprogramming the car. Hopefully I get my ZCP EDC programming back, good reason to do this at the dealer I think. Should be covered by my extended warranty, fingers crossed.

[///Mobbin]

Originally Posted by spr

Did you buy a new coded zcp etc module? If not they don't take the programming. We tried on 2 modules.

The BMW dealer is sourcing the module, will ask what part number module and let you know.

And BTW, they also said they have to update the programming on the car in general so all the modules are communicating correctly. Curious if that may have been part of your issue.

[spr]

There are only 2 pns. Make sure they get the newer seimens unit with the zcp preprogrammed.



QUOTE=///Mobbin;20563584]The BMW dealer is sourcing the module, will ask what part number module and let you know.[/QUOTE]

[///Mobbin]

Originally Posted by spr

There are only 2 pns. Make sure they get the newer seimens unit with the zcp preprogrammed.

Will do and thanks! Do you have the p/n by chance?

[spr]

Not offhand but old one is continental, new is segment, but it must be preprogrammed with zip if your car didn't have it factory.

Originally Posted by ///Mobbin

Will do and thanks! Do you have the p/n by chance?

[///Mobbin]

Leaving this here for others, the pn for at least one of the units appears to be:
37156788790, can't tell which one, LINK.

[Helmsman]

Originally Posted by ///Mobbin

Leaving this here for others, the pn for at least one of the units appears to be:
37156788790, can't tell which one, LINK.

According to the ad seems to be one fit all. Still the same part no as my ZCP. Is there more than one version hw..?

[///Mobbin]

Originally Posted by Helmsman

According to the ad seems to be one fit all. Still the same part no as my ZCP. Is there more than one version hw..?

It looks like the p/n 37156788790 EDC-K Control Unit is the one they installed in my car. Still trying to confirm with the tech that the ZCP programming was done.

[whats77inaname]

Benvo provided some really good input on this thread regarding the telltale sign that the issue is the EDC....

www.m3post.com/forums/showthread.php?t=1283704

[jgbedford]

Originally Posted by Lunker325

Currently I have my faulty EDC module unplugged, car is riding very firm, but no more battery discharge errors.

Sorry to revive an old thread, did you have any negative impacts after unplugging the module? I don’t have time to get a replacement right now and can’t plug the car in every night. Is unplugging the module a short term fix to isolate the problem? Did it cause any other error codes?

[Lunker325]

Originally Posted by Jbedford

Sorry to revive an old thread, did you have any negative impacts after unplugging the module? I don’t have time to get a replacement right now and can’t plug the car in every night. Is unplugging the module a short term fix to isolate the problem? Did it cause any other error codes?

No worries, glad to help! I did not have any issues from unplugging the module besides the error code and the car riding more firmly. This worked for me for a couple of weeks. As a long term update, I never did end up coding the replacement module I got off of Ebay. The module works fine, EDC acts as it should, and no battery drain since the install. The module I bought was from a non competition equipped car, same as mine, which may be why it works fine with no coding to the car.