Can battery control module failure cause batteries to drain??
Thread Starter
MBWorld Fanatic!
Joined: May 2007
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From: San Diego
2004 E55
Can battery control module failure cause batteries to drain??
I suspect that my battery control module (BCM) is bad, though I don't know how exactly to confirm it. I have ran through about 4 batteries in the 3 years that I've had the car and that seems way too high. Right now both batteries are WAY under voltage - 8v for the under-hood battery and 5v for the main battery. The main battery is about 6 months old. The alternator is roughly 2 years old; was replaced (which I am told includes voltage regulator) at a Mercedes dealer. The under-hood battery is also roughly 2 years old.
The reason I suspect the BCM is because there are 4 new part numbers since the original one was released with my car. The car is a 2004 and I have the original part number module, and when I called Mercedes to inquire, the parts guy told me that there were upgrades and that my part number was now obsolete. I have also read posts in this forum saying that the original design was defective...?
The car is a 2004 E55 and is about to turn 97 thousand miles. Any thoughts?? Thanks.
The reason I suspect the BCM is because there are 4 new part numbers since the original one was released with my car. The car is a 2004 and I have the original part number module, and when I called Mercedes to inquire, the parts guy told me that there were upgrades and that my part number was now obsolete. I have also read posts in this forum saying that the original design was defective...?
The car is a 2004 E55 and is about to turn 97 thousand miles. Any thoughts?? Thanks.
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From: Caribbean/Florida/Colorado
E-ZGO 53hp., 1999 E 430 sport, 2004 E 55, 2008 Tahoe LTZ on 24"s
There are at least 4 software updates too.
https://mbworld.org/forums/1256180-post2.html
Is your car going in to sleep mode?
https://mbworld.org/forums/1256180-post2.html
Is your car going in to sleep mode?
Last edited by Yacht Master; Aug 14, 2011 at 10:29 PM.
Thread Starter
MBWorld Fanatic!
Joined: May 2007
Posts: 1,793
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From: San Diego
2004 E55
I saw that post this morning and I'm going to call a few dealerships tomorrow morning. I'm not sure what sleep mode is actually, but the car was driven yesterday, and I had to jump it today to get it to start.
What do you think are my odds at getting them to do the software update??
What do you think are my odds at getting them to do the software update??
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E55, SL63, ML550
The BCM controls consumer shutoff and can give erroneous messages, but rarely if ever have I seen one actually cause a draw itself. You need to start with charged/good batteries, and then test for a draw-- car locked and asleep.
Thread Starter
MBWorld Fanatic!
Joined: May 2007
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From: San Diego
2004 E55
I was also under the impression that it dictates how the batteries - specifically the auxiliary battery - is charged. Is this not so?
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Joined: Oct 2010
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E320
I am having a similar problem with my 2004 E320 for about 6 months. I did a lot of investigation but still have not solved the problem:
1. Periodically drains battery at about 2.2 amps. I use a clamp on ammeter to measure this. Once occurred, it will continue to do so until the battery is either drained or disconnected for several hours. This started at the period of about 6 months to weekly and now every 2-3 days.
2. I replaced the battery, it did not fix it.
3. I had a service shop (not MB) disconnected every fuse one at a time. It did not stop the 2.2 amps drain.
4. If fully charged, it will start after 8 hours but with the convenient function disabled
5. I took it to MB shop twice when it was draining, but it stopped the drainage before the mechanics found the problem.
6. I am checking the drainage rate every day now and wait until it happens all the time before taking it to the MB shop again.
Does anyone have a suggestion?
1. Periodically drains battery at about 2.2 amps. I use a clamp on ammeter to measure this. Once occurred, it will continue to do so until the battery is either drained or disconnected for several hours. This started at the period of about 6 months to weekly and now every 2-3 days.
2. I replaced the battery, it did not fix it.
3. I had a service shop (not MB) disconnected every fuse one at a time. It did not stop the 2.2 amps drain.
4. If fully charged, it will start after 8 hours but with the convenient function disabled
5. I took it to MB shop twice when it was draining, but it stopped the drainage before the mechanics found the problem.
6. I am checking the drainage rate every day now and wait until it happens all the time before taking it to the MB shop again.
Does anyone have a suggestion?
Last edited by TUngpiyakul; Dec 23, 2012 at 12:59 PM.
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MBWorld Fanatic!
Joined: Apr 2008
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From: Queens, NY
04 w211 E55
I had my battery control module changed a couple years ago for about $2300 :/ at the dealer. I do know that it didn't kill my battery though. My original battery died further down the road and I had it replaced with a crappy battery because my car was stuck in the street and I went to strauss and bought whatever they had and that battery just died on me yesterday. Maybe the batteries your buying is as crappy as the one i had bought less than a year ago that is now completely shot
Newbie
Joined: Oct 2010
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E320
Thanks for the info. I was hoping that the BCM was your problem. I know that my problem is something draining the battery at the rate of 2.2 amps. I just don’t know what. When the ammeter indicates that is draining it, it will get weak in about 6 hours and die after 12 hours. I already spent about $400 but the problem is still there. It looks like the BCM is not hard to replace; I might just do it myself.
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From: Jacksonville, FL
05 White Pano E55, Cadillac CTS-V
I had my battery control module changed a couple years ago for about $2300 :/ at the dealer. I do know that it didn't kill my battery though. My original battery died further down the road and I had it replaced with a crappy battery because my car was stuck in the street and I went to strauss and bought whatever they had and that battery just died on me yesterday. Maybe the batteries your buying is as crappy as the one i had bought less than a year ago that is now completely shot
I know they are known as the stealership but I don't see how that is even possible they could rape you that bad. That would be like 15 hours labor or something crazy. The unit itself I just bought for $344 (not including shipping) new from GenuineMercedesparts.com and they are listed at $430 which I would assume is a dealer price. And then it is literally a less than 5 minute job to replace.Also, I ended up not needing it since my voltage regulator was bad and fixed my low voltage problem (car would go from reading 14 volts to 11 and back and forth when it wanted). I am about to return the battery control module if I can unless someone wants to buy it for like $300 shipped.
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Joined: Apr 2008
Posts: 1,762
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From: Queens, NY
04 w211 E55
$2300 to buy/change a battery control module? I know they are known as the stealership but I don't see how that is even possible they could rape you that bad. That would be like 15 hours labor or something crazy. The unit itself I just bought for $344 (not including shipping) new from GenuineMercedesparts.com and they are listed at $430 which I would assume is a dealer price. And then it is literally a less than 5 minute job to replace.
Also, I ended up not needing it since my voltage regulator was bad and fixed my low voltage problem (car would go from reading 14 volts to 11 and back and forth when it wanted). I am about to return the battery control module if I can unless someone wants to buy it for like $300 shipped.
I know they are known as the stealership but I don't see how that is even possible they could rape you that bad. That would be like 15 hours labor or something crazy. The unit itself I just bought for $344 (not including shipping) new from GenuineMercedesparts.com and they are listed at $430 which I would assume is a dealer price. And then it is literally a less than 5 minute job to replace.Also, I ended up not needing it since my voltage regulator was bad and fixed my low voltage problem (car would go from reading 14 volts to 11 and back and forth when it wanted). I am about to return the battery control module if I can unless someone wants to buy it for like $300 shipped.
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Joined: Feb 2011
Posts: 1,752
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From: London, UK
W212 - E63 AMG
I am having a similar problem with my 2004 E320 for about 6 months. I did a lot of investigation but still have not solved the problem:
1. Periodically drains battery at about 2.2 amps. I use a clamp on ammeter to measure this. Once occurred, it will continue to do so until the battery is either drained or disconnected for several hours. This started at the period of about 6 months to weekly and now every 2-3 days.
2. I replaced the battery, it did not fix it.
3. I had a service shop (not MB) disconnected every fuse one at a time. It did not stop the 2.2 amps drain.
4. If fully charged, it will start after 8 hours but with the convenient function disabled
5. I took it to MB shop twice when it was draining, but it stopped the drainage before the mechanics found the problem.
6. I am checking the drainage rate every day now and wait until it happens all the time before taking it to the MB shop again.
Does anyone have a suggestion?
1. Periodically drains battery at about 2.2 amps. I use a clamp on ammeter to measure this. Once occurred, it will continue to do so until the battery is either drained or disconnected for several hours. This started at the period of about 6 months to weekly and now every 2-3 days.
2. I replaced the battery, it did not fix it.
3. I had a service shop (not MB) disconnected every fuse one at a time. It did not stop the 2.2 amps drain.
4. If fully charged, it will start after 8 hours but with the convenient function disabled
5. I took it to MB shop twice when it was draining, but it stopped the drainage before the mechanics found the problem.
6. I am checking the drainage rate every day now and wait until it happens all the time before taking it to the MB shop again.
Does anyone have a suggestion?
Newbie
Joined: Oct 2010
Posts: 10
Likes: 0
E320
If it is the same problem as mine, the frequency will get shorter. In my case, the time from the first to second occurrence is about a year. Now it is every 2 -5 days of driving. It acted like something got started and never stopped even after the key has been taken out. If your problem continues and you want to deal with it (using the red neck method), let me know I will post the detail. Mine happens every 3 – 7 days of driving, but I never need a jump start since I implement this (somewhat hilarious method). It needs about $100 worth of parts, though.
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Joined: Jan 2009
Posts: 3,182
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From: Northern VA
W211
Similar to me. Replaced the volt regulator, new aux battery, front battery relay and battery control module in trunk. No more low battery conv functions disabled or the red battery code . I replaced ez h part one by one until the codes cleared themselves. Car now sits at 14.4 when running. .
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From: London, UK
W212 - E63 AMG
Newbie
Joined: Oct 2010
Posts: 10
Likes: 0
E320
Here is what I did:
1. Extend the negative terminal out so that it can be accessed when the trunk is open. I use another battery terminal cable for this.
2. Extend the positive terminal out so that it can be accessed when the trunk is open. The cable here has an insulated cap at the end so that it can be open to charge the battery.
3. Every night after driving is done, I check the battery drainage using a clamp-on ammeter on the negative terminal (after the car is in sleep mode).
4. The first few times it was draining, I pulled every fuse but the drainage never stopped. I charge the battery overnight using a trickle charger. It went on for days and never stopped. I took it to the MB service but it stopped before they found the problem.
5. Currently after I detect the drainage, I charge the battery overnight first. If it does not stop, I disconnect the battery the next evening. The problem went away for 3 – 5 days after the battery disconnection.
I will wait until it happens more frequently before I take it to the shop. I think I will duplicate what NOVAE500 did to see if it will fix my problem.
1. Extend the negative terminal out so that it can be accessed when the trunk is open. I use another battery terminal cable for this.
2. Extend the positive terminal out so that it can be accessed when the trunk is open. The cable here has an insulated cap at the end so that it can be open to charge the battery.
3. Every night after driving is done, I check the battery drainage using a clamp-on ammeter on the negative terminal (after the car is in sleep mode).
4. The first few times it was draining, I pulled every fuse but the drainage never stopped. I charge the battery overnight using a trickle charger. It went on for days and never stopped. I took it to the MB service but it stopped before they found the problem.
5. Currently after I detect the drainage, I charge the battery overnight first. If it does not stop, I disconnect the battery the next evening. The problem went away for 3 – 5 days after the battery disconnection.
I will wait until it happens more frequently before I take it to the shop. I think I will duplicate what NOVAE500 did to see if it will fix my problem.
Last edited by TUngpiyakul; Dec 27, 2012 at 10:05 AM. Reason: Improve readibility
Member
Joined: May 2011
Posts: 160
Likes: 1
From: NY
2005 E55 AMG
You see that's BS there is no relay for the F***KIN AUX there is only a BCM that controls all OK!!! Srry I have been going through this prob since OCT. I am losing my mind. I can't stand it every1 asks about my AMG and I have to come up with something to lie and make a excuse. If there is a aux relay PLZ PLZ GIVE ME D PART NUMBER
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Joined: Jun 2013
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From: 'Merica
'04 E55 (Gone but not forgotten), '13 C63 P31 (RIP), another '13 C63 PP
You see that's BS there is no relay for the F***KIN AUX there is only a BCM that controls all OK!!! Srry I have been going through this prob since OCT. I am losing my mind. I can't stand it every1 asks about my AMG and I have to come up with something to lie and make a excuse. If there is a aux relay PLZ PLZ GIVE ME D PART NUMBER
It seems like you have had a lot of different problems with your E... Was it a flood car or something?
Member
Joined: May 2011
Posts: 160
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From: NY
2005 E55 AMG
