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Discussion Starter · #1 ·
I have been doing component-level electronic repairs for the past 50 years. I have an educated hunch at which type of component(s) are going bad in the BECM. I would love to get my hands on one to see if I could repair it. If I can fix one, I could probably fix nearly all of them.
 

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From another thread:

If anyone has a BECM that has failed and wants it repaired, please let me know and we can arrange to have it sent to me for inspection. If it cannot be repaired I will return it in the same condition at my expense. If it can be repaired, I will do the first one at no charge.
For those with long wait times on replacement BECM's this could be of interest.
 
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It would be interesting to crack open of those BECM modules open and see if there is any obvious burned components. I've wondered why the Gen 2 is having so many go bad. Most of the modules I've seen for the Volts have MADE IN JAPAN stickers on them. That use to be a bad thing, now as we all know Japan is one of the leaders in manufacturing design and quality. Especially automotive and electronics. Being located on top of the battery could possibly getting hotter than the engineers thought it would? If you could narrow down the component level culprit it would most likely be a surface mount part. Not a problem to replace with the right soldering tools/bench. If it is a surface mount IC issue, I've found a lot of those are proprietary chips designed specifically for that module. So you might run into the same issue the manufacture is having getting the chips. But definitely worth opening one up and taking a look.
 

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Discussion Starter · #4 ·
Actually, I do not expect it to be an IC issue, so I do not expect to have any issues with part availability. But you are correct that it is most likely heat- and age-related. I just need one to prove my theory.
 

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I agree... I suspect fractured solder joints more than failed ICs. It's often the case that a PCB will have inadequate pad space for the soldered joint to a higher amperage component and over time, it fractures due to heat. In addition, manufacturers have moved to more eco-friendly solders which can be more subject to this. So it will indeed be interesting to do a deep dive on a failed BECM to determine the real failure mode.
 

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One guy tried to repair the BECM. He discribes, that he eventually had to disassemble the car 11 times before he decided to buy a new one. It was some time ago.

He says they tried resoldering components. It seemed everything started to work, but after a day or two of driving it started failing again. Then they tried to freeze the module in the fridge after resoldering and it caused it to fail.

After some time he said they managed to repair, but again after a couple of months he decided to install a new one.

So, not knowing the real cause I think it's almost impossible to repair it, especially without bench testing and road testing.
 

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It would seem to be an exercise in futility trying to "fix" the module without the factory test fixture with diagnostic CAN bus software. It would be useful to have it running balance routines and temp ranges with a program/environment that puts the module through the paces of the lookup tables. Conformal coating is also a bitch to work with...no thanks.
 

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Ambitious project for sure, if someone can find a fix for these a lot of Gen 2 owners would be more than grateful. Especially in the next few years as the 8 year warranty expires to fix these for free. The first hurdle, getting your hands on a bad one will be difficult. The only folks that will have access to one will be the dealerships that are replacing them under warranty. Need one of the Volt techs out there to send one to you instead of tossing it in the dumpster or in the bottom or their tool box with the other bad modules. I would think if someone with a garage and lift could successfully repair problems like this and replacing battery sections or even cell packs they could do very well. Especially if gas prices remain where they are now. A Volt that became a lawn ornament is now highly sought after.
 

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Does anyone know who the OEM maker of this module is?
It’s probably Bosch, Lear, or Delphi. I’m positive I’ve recently seen a photo of the circuit board of the BECM on one of the forums.

Update: I found the photo on the FB Volt modding and repair forum. The logo on the board shows it to be made by LG:

Passive circuit component Circuit component Product Hardware programmer Microcontroller
 

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Discussion Starter · #14 ·
It’s probably Bosch, Lear, or Delphi. I’m positive I’ve recently seen a photo of the circuit board of the BECM on one of the forums.

Update: I found the photo on the FB Volt modding and repair forum. The logo on the board shows it to be made by LG:

View attachment 174767
Because the BECM is used on a vehicle, outside causes of damage such as lightning are eliminated, so defective proprietary ICs are highly unlikely. Other causes of damage are vibration (circuit pattern failures), under-rated parts that prematurely fail, and failures caused by heat and/or age. Defective circuit patterns are only slightly more likely than failed ICs, and would be very difficult, if not, impossible to repair. If the photo above is showing a BECM circuit board, then it will be a matter of removing a few parts, testing their values, replacing them with new identical parts, and having the module re-installed to confirm that the problems were resolved. I have been doing these types of repairs for many years and I am actually encouraged by a previous post that indicated that heating and cooling the board seemed to make a difference.
 

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where are you located? I'm in MD and while my BECM is still good for now, GM probably won't warranty mine if it goes bad due to my salvage history. PLan A would be to jerry rig it to always be on. PLan be would be to buy a wrecked one with the vin history showing becm replaced and swap it over.. or one with a dead battery..
 

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LG is a Chinese company, isn't it? Either way, that explains a lot. Like my LG washer and dryer that malfunctioned and needed warranty repairs. Shame on GM
LG is one of the largest Korean Chaebols.

My LG washer is 7 years old and works like a charm.... However, I've noticed that as that model has evolved (my in-laws bought its successor) the programing on the board has changed. Some changes for the better... Some for the accountants...
 

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Because the BECM is used on a vehicle, outside causes of damage such as lightning are eliminated, so defective proprietary ICs are highly unlikely. Other causes of damage are vibration (circuit pattern failures), under-rated parts that prematurely fail, and failures caused by heat and/or age. Defective circuit patterns are only slightly more likely than failed ICs, and would be very difficult, if not, impossible to repair. If the photo above is showing a BECM circuit board, then it will be a matter of removing a few parts, testing their values, replacing them with new identical parts, and having the module re-installed to confirm that the problems were resolved. I have been doing these types of repairs for many years and I am actually encouraged by a previous post that indicated that heating and cooling the board seemed to make a difference.
Once upon a 1980s, back when CD players were part of Stereo component racks, (and when dinosaurs roamed the earth), I had a Sansui CD player that decided to stop working and instead of paying $600+ for a replacement model, I took it to a Sansui-authorized repair facility. He did a solder repair and got it working and returned it to me (I paid $100). I got it home (the thing travelled in its original box with styrofoam). It decided to stop working the next day, so I took it back (he had warrantied the repair for 90 days). He fiddled with it again and got Sansui to agree to examine it, so he shipped it to the west coast. Sansui, upon receiving it, said it worked just fine and sent it back to him. He uncrated it and it was DOA. Two more round trips to the west coast over the next month resulted in the same situation. So he re-soldered every connection on the entire board, got it to work and returned it to me. Amazingly it worked well into the 1990s when I finally gave away the entire system.

I wouldn't be surprised if it were a solder failure (caused by either vibration or heat/cool expansion/contraction) that there might be many connections that will fail over time over the entire board. Both the Japanese and Korean engineers are very consistent in what they engineer electronically. The bigger question is whether the specs for heat cycle and vibration were given to them for this particular component.
 
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