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Missing Components For Battery Control Module

960 Views 20 Replies 10 Participants Last post by  Witek_M
Hey Guys,

A quick back story. i bought the car as a project to learn more about cars, this forum has been very helpful so far.
while buying the car the trunk did not open and the seller did not mention anything wrong with the car other than the ones that are visible.

i got home and after a few days of sitting on the car i managed to get the trunk open and at that point i wish i ddnt. the car had burn marks on the right next to the wheel well. things were missing and pipes were cut.

i brought this up in a previous thread about my temperature light wont go off but i thought i would create a new thread in case anyone else had a similar issue and can find the solutions.

to my knowledge that is where the BCM is Located and i managed to find it burnt to a crisp in the trunk. i will post a few photos of the damage and hopefully some of you could help me identify what it is exactly that i am missing for me to purchase.

many thanks in advance.
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Hey Guys,

A quick back story. i bought the car as a project to learn more about cars, this forum has been very helpful so far.
while buying the car the trunk did not open and the seller did not mention anything wrong with the car other than the ones that are visible.

i got home and after a few days of sitting on the car i managed to get the trunk open and at that point i wish i ddnt. the car had burn marks on the right next to the wheel well. things were missing and pipes were cut.

i...
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1 - 20 of 21 Posts

· Registered
95 SL600
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1,523 Posts
This is a common problem, and it’s a real bad problem. It’s a terrible design and turning much more dangerous as time goes by. Very close to getting rid of the two cars I have if there isn’t a resolution to this. Not something that makes me happy to own these POS cars with all of the other problems they have.
 

· Registered
2003 SL 350
Joined
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33 Posts
Discussion Starter · #3 ·
Thats sad to hear. i did my research and yes it is a very common issue, i just wanted to know if there are any parts that are missing I should add to my basket. other that the BCM.

thank you
 

· Registered
'03 SL500's Tanzanite Blue, Aegean Blue, Mars Red, Alabaster White '11 S550 Flint Gray
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408 Posts
That's bad. Any insurance estimate on this would end up totaling the car. It can be fixed, but will take a good amount of money and a LOT of time. If you don't have the time or ability to DIY it, I would recommend dumping it and cutting your losses.

Here is what it should look like. You would need the BCM, K57 and K75 relays, wiring, right side frame lock with cylinder, main cylinder, and load assist cylinder. PSE lines to fuel door and central locking? need replaced as does keyless go antenna. Main issue will be wire harness replacement. You did dodge one bullet, an ABC strut would have been destroyed.
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· Registered
2003 SL 350
Joined
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33 Posts
Discussion Starter · #8 ·
That's bad. Any insurance estimate on this would end up totaling the car. It can be fixed, but will take a good amount of money and a LOT of time. If you don't have the time or ability to DIY it, I would recommend dumping it and cutting your losses.

Here is what it should look like. You would need the BCM, K57 and K75 relays, wiring, right side frame lock with cylinder, main cylinder, and load assist cylinder. PSE lines to fuel door and central locking? need replaced as does keyless go antenna. Main issue will be wire harness replacement. You did dodge one bullet, an ABC strut would have been destroyed.
Big Ups to you mike and thanks for the list, ill look into the parts. this will be an expensive one 🤣

any bumps i face down the road ill reach out for help if thats fine with you.

thanks.
 

· Registered
2003 SL 350
Joined
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33 Posts
Discussion Starter · #9 ·
Damn, first I heard of this.
So what is the problem? Water leak shorts out and causes fire?
water does seem like the probable cause of it. i confronted the seller and he pleaded ignorance and said the trunk did not open for him and he never checked.. so it is what it is.

plus apparently the Battery control modules have been known to just explode and catch on fire for some reason.
 

· Registered
SL600 (R230), E320-4M (W210)
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48 Posts
I gotta second the suggestion that you should consider declaring victory and dumping the car. You've got (at least) one of the three most expensive phrases in the English language on your hands:

"I do"
"...while I'm at it..."
"cheap Mercedes"
 

· Registered
2005 R230 SL350 (M112)
Joined
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442 Posts
Edited-sorry

Warith, if there is an after market out there you will be better off parting out the car. Some parts can fetch real money and many are equal or similar to bigger engined R230's. And as you go you'll learn from it. This car is doomed.
 

· Registered
2005 SL 500 R230
Joined
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458 Posts
If there is any legal comeback in your land, I'd be looking at it. That is out and out fraud, tantamount to theft. There is no possible way whoever sold you that car could not have known about the damage. If not, parting it out is a good plan.
 

· Registered
Dallas, Texas
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13,073 Posts
Damn, first I heard of this.
So what is the problem? Water leak shorts out and causes fire?
Here is scenario that may explain failure like this.
R230 is known for excessive parasitic consumption.
Systems (rear) battery is at 7.2V. You put key in ignition, dude with jumper cables (starter battery) powers up the system and vehicle starts. That's when things go wrong. Since alternator is not controllable all it does is ramp up voltage to 14.2V and whatever current output it has. ~150A.
20A goes towards vital vehicle functions, rest of it goes towards batteries. Things start getting warm.
If systems battery has dead (shorted) cell. Normal with deeply discharged batteries, alternator will try to maintain 14.2V.
And that's when smoke starts. Rest of it is just a matter of time.
 

· Registered
2003 SL 350
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33 Posts
Discussion Starter · #16 ·
Honestly, this forum has been very helpful and I do appreciate all the help.
I guess you win some and you lose some.

and in this case, my wallet is the one losing badly 😂 I can't help but just laugh.

i guess ill try to fix some of the mechanical issues and try to sell it as the bcm being the only issue. and if no buyers ill give it a shot myself to try and fix it as I am already too deep in the mud and no point in turning back.

appreciate the help you lot, and if my stubborn self decides to continue with the car you will surely see a few more threads popping up.
 

· Registered
2003 SL 350
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33 Posts
Discussion Starter · #17 ·
Edited-sorry

Warith, if there is an after market out there you will be better off parting out the car. Some parts can fetch real money and many are equal or similar to bigger engined R230's. And as you go you'll learn from it. This car is doomed.
this model year is very rare here as most people only prefer driving 2010 and up.. i dont even see the car up for sale in the market place so i am basing the value of the car on Dubai's market who are our neighbour
 

· Registered
2003 SL 350
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33 Posts
Discussion Starter · #19 ·
Put the wiring back together with a new bcm, splice the vacuum lines, make sure it has new batteries, and most importantly park it outside away from important things. Not too rainy there
yeah that's something i am looking to do, i just need to find the parts and get it done. and yeah it rains once a year over here 🤣 🤣 🤣 .

but yeah appreciate the help guys.
 
Joined
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34 Posts
Awful to see this damage..Is it caused by water seepage or a dead battery cell/s and / or the alternator frying the battery as mentioned ? What can be done to prevent others from enjoying such an experience ?..I have an sl60 and keep her in the garage during winter time and both of her batteries are on trickle chargers ..I start her bi weekly ..Any prevetitive advice is most welcome ....Sorry I can't contribute any helpful advice / information...
It's great that there are fellow MB guys that offer help ..My dealer would only smile and say bend over..Good luck with repairs.
 
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