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Attempting to hack a Chevy Volt Drivetrain

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#41 · (Edited)
kerrymann said:
Duh, precharge resistors. Of course, it's obvious now. I was looking for a heater and saw those and jumped to the wrong conclusion. I will correct it. Thanks.

There are a couple other things I need to change or update in the videos. I find myself having time to work on the cars, or shoot videos, or edit the stuff, but not the time to do all of them. I tried having a family friend with the video editing (hence the goofy intros) but it did not work out.

Anyway, I will send you a PM. There is already a group of about a dozen of us working on the volt and the leaf and the more the better
Click to expand...
I would love to join! I just got half of a volt battery (the end-two 72v/54s modules), a front relay module as well as a control module (HIGH VOLTAGE BAT Volt 24 Channels). I'm looking around for an ECM and am definitely interested in haxoring the CAN interface. Send me a PM if interested/possible.

Also let me say you have some Great videos!!! The the VanHalen logo on the battery ends, I would Pay good money for ends like that!! I would be interested in learning more about the bolt sizes you need for the bolts?

I'll be studying your videos alot. :) Thanks for them!!
Kris
 
#42 ·
I would like to help on the project where ever I can. I have a 2012 Volt with GDS2 software and MDI module. I am going to get a Y adapter for the OBD port so I can sniff traffic with a OBDMX bluetooth adapter while running diag. I also have the service manual.
 
#43 ·
kerrymann said:
Besides the obvious stuff get the charger on the passenger side front bumper if It is not damaged (Often it is). It has been hacked and its a nice unit.
Click to expand...
OK this is awesome. I was just thinking about what I should do for a charger... I am planning on using chevy volt battery packs for my rx8 conversion.

Where can I find the hack information on the chevy volt charger?? What hardware do I need to get it to work?

Thanks for any info you can give!!

I watched your vids on the volt battery BTW and I am convinced to go that route. The performance and the savings over LifePO4 is too good to pass up. 600KW should be enough lol :D:D
 
#45 ·
Well I guess it depends how much C code you want to write... EVTV seems to sell their CANDue (modified Arduino clone it seems) that they use to control all sorts of CAN Bus devices. I have never used one so I cannot say much beyond that.

On the form link above people shared some CAN Bus captures of the Chevy Volt changer working, and it seems all the information is there to write your own software with full control. What feels like forever ago I parsed over the CAN data on the form and felt there was more useful data to be decoded but as no one ever replied I guess either that form is dead, I am wrong, or no one really cares... Personally I wish there was a site with CAN dumps that I could browse through and analyze since I find that fun, (I know there are things wrong with me :eek:)
 
#46 ·
Does anyone have any logs of communications with the cell monitors/managers that are located on the battery packs on a Volt? I picked up a complete 2013 Volt battery and I'd like to use the cell monitors. I'm not using the Volt charger equipment, either.

I am using a USB to CAN interface and Wireshark for haxors and I can see lots of broadcast info, but I don't have a Volt to sniff to see the commands going back to the cell monitors. I don't think the CAN lines from the pack modules are passed through to the main chassis CAN lines (2500/2501), so someone would probably need to tap into the lines on the battery pack itself. I can do this, but I don't have a Volt and I think that might be a real challenge to get to.
 
#47 ·
Well I spent a few hours logging all the CAN buses I could identify on a 2012 Volt tonight. I haven't done much with the data yet, it's time for bed. The files are too big to attach on a forum post so I'll upload them and post them tomorrow.
 
#48 ·
I'll drop this here in case anyone really wants to get into it. These are 3 giant logs exported as a CSV from Wireshark. I had to split it up into 3 files because there are 2.5 million messages, nothing filtered out. This log was taken from the AUX DLC port CAN bus that's connected to the HPCM2 and charge controller (2012 Volt). I grabbed logs from all the other ports in various conditions, I'll post them as I get through them.

For this log, we got in the car, I started logging and there was no activity. The car was removed from the charger in the minute before we started. I started the log, then we turned the car on and drove around to use up some charge. The dash indicator said we used 1.5kwh. Still logging, we pulled in to park, shut it off, let activity stop on the bus.

Then we plugged the charger (L2) in and let it charge until all bus activity stopped when the car was fully charged, about 30-40 minutes. This bus has continuous activity during the charge, but otherwise nothing when the car is off. I checked all of the other CAN busses on both DLC's and they all have a short burst of messages when the charger is first connected, but then stops completely. They have nothing continuous during the actual charging phase.

https://www.dropbox.com/s/mfbh3w7d68sp3ux/Volt_LOG_11.zip?dl=0
 
#49 · (Edited)
Have the CAN logs from a full Volt been posted anywhere? I'd love to help with this. In the process of acquiring a used Volt pack for a solar project, and I have a lot of spare time to dig into CAN hacking the onboard BMS.

Based on
http://www.edn.com/Home/PrintView?contentItemId=4391497
https://docs.google.com/file/d/0BwHvhEbCHHEleUp3TUMxOUwzdmM/edit

It seems like the data that's most interesting is between the Battery Energy Control Module on the front of the pack, and the Battery Management Module under the passenger seat.

(edit)
Oh hey, found elsewhere on this forum that this is actually pretty easy if you're using the whole battery pack at it's full voltage:
http://www.diyelectriccar.com/forums/showpost.php?p=842810&postcount=544

Because I plan to split these up into parallel 48V units for solar, I think I'll still dig into the module communication itself though.
 
#50 ·
Anymouse said:
Have the CAN logs from a full Volt been posted anywhere? I'd love to help with this. In the process of acquiring a used Volt pack for a solar project, and I have a lot of spare time to dig into CAN hacking the onboard BMS.

Based on
http://www.edn.com/Home/PrintView?contentItemId=4391497
https://docs.google.com/file/d/0BwHvhEbCHHEleUp3TUMxOUwzdmM/edit

It seems like the data that's most interesting is between the Battery Energy Control Module on the front of the pack, and the Battery Management Module under the passenger seat.

(edit)
Oh hey, found elsewhere on this forum that this is actually pretty easy if you're using the whole battery pack at it's full voltage:
http://www.diyelectriccar.com/forums/showpost.php?p=842810&postcount=544

Because I plan to split these up into parallel 48V units for solar, I think I'll still dig into the module communication itself though.
Click to expand...
The logs are posted, yes. They are large, so be patient... https://www.dropbox.com/s/mfbh3w7d68sp3ux/Volt_LOG_11.zip?dl=0 This file contains 2.5 million CAN messages logged on the HV CAN bus. It starts just sitting with the car off, then we go for a 15 minute drive, then plug it in to charge to 100%.

The modules - BECM is in the battery pack and the HPCM2 is under the passenger's seat. Charging, balancing, and the like are actually commanded by the HPCM2, not the BECM. The cell voltage, temps, current sensors, and a couple other things have been figured out. What I still haven't found is what the HPCM2 sends to the BECM to tell it to balance cells.

But I'm going to figure it out. I bought the HPCM2 from the actual Volt my pack came out of on Friday and I will try to get it fooled. The have a feeling the balancing command(s) are rare since the packs are so consistent.
 
#51 · (Edited)
Perfect, thanks!

Based on that other forum post by jontscott, I looked into 0x202 etc. for the individual cell voltages and could definitely spot them in there. I searched high and low and couldn't find anyone's info for parsing the bits - so here's what I could reverse engineer myself from scratch (in case anyone else finds this).

Grab CAN IDs 0x200, 0x202, 0x204, and 0x206. Parse out the bits like this:

3 - ignore
12 - cell voltage A
4 - ignore
12- cell voltage B
1 - ignore
12 - cell voltage C
7 - packet number
10 - ignore

Each CAN ID sends 8 packets, (packet number 0 through 7), and each packet has three voltages. There's four CAN IDs, so 4 * 3 * 8 = 96, which is the number of cell sets in the Volt pack.

It's a total guess, but if you divide the cell voltage values by 800 - you get what looks a lot like the actual figure. This could be wrong! I don't have a volt pack to double check with a voltmeter. But from what I can tell 4.06V is fully charged, so that number works out with this CAN dump.

Here's an annotated snippet of my raw dump, with iterative parsing:

Code: 
Timestamp   Can ID  ign   voltage A   ign    voltage B     voltage C   pktnum   ignore         vA     vB     vC  p        voltA voltB voltC
3400.101046  [200] [000 110010110110 0111 110010110101 0 110010110110 0000001 1100000000 ] [0 3254 7 3253 0 3254 1 768 ] [4.068 4.066 4.068 ]
3400.101254  [202] [000 110010110101 0111 110010110100 0 110010110101 0000001 1100000000 ] [0 3253 7 3252 0 3253 1 768 ] [4.066 4.065 4.066 ]
3400.101490  [204] [000 110010110101 0111 110010110101 0 110010110100 0000001 1100000000 ] [0 3253 7 3253 0 3252 1 768 ] [4.066 4.066 4.065 ]
3400.101727  [206] [000 110010110101 0111 110010110010 0 110010110101 0000001 1100000000 ] [0 3253 7 3250 0 3253 1 768 ] [4.066 4.063 4.066 ]
3400.126331  [200] [000 110010110100 0111 110010110110 0 110010110101 0000010 1100000000 ] [0 3252 7 3254 0 3253 2 768 ] [4.065 4.068 4.066 ]
3400.126554  [202] [000 110010110101 0111 110010110101 0 110010110101 0000010 1100000000 ] [0 3253 7 3253 0 3253 2 768 ] [4.066 4.066 4.066 ]
3400.126792  [204] [000 110010110101 0111 110010110101 0 110010110110 0000010 1100000000 ] [0 3253 7 3253 0 3254 2 768 ] [4.066 4.066 4.068 ]
3400.127041  [206] [000 110010110101 0111 110010110100 0 110010110100 0000010 1100000000 ] [0 3253 7 3252 0 3252 2 768 ] [4.066 4.065 4.065 ]
3400.151142  [200] [000 110010110110 0111 110010110101 0 110010110110 0000011 1100000000 ] [0 3254 7 3253 0 3254 3 768 ] [4.068 4.066 4.068 ]
And here's a CSV of what all your 96 of your cell voltages looked like throughout that entire dump (every 100ms or so!). http://scrunk.com/volt-cell-log.csv.zip

I'm going to keep digging in here and see if I can find other useful IDs. I think you're right about balancing though - it may not start until it sees a cell out of whack, so the only way to catch it in the act might be to manually bleed down one cell by 0.1V or so and see if we can cause it to send the balance command.

Also I am very interested in seeing if your HPCM2 works as expected when it isn't part of the rest of the car. If that goes properly, I would love to get a capture from the 125kbps CAN bus between the BECM and the modules themselves. That'd allow folks to split them up and use them for solar without having to keep the whole pack intact at high voltage, and also avoid getting a pricey third party BMS.

edit:

To keep all the info in one place, I'll just put CAN IDs here as I find them:

Code: 
=== Confident ===
0x200:   3, 12, 4, 12, 1, 12, 7, 10    ???, cell voltage, ???, cell voltage, ???, cell voltage, cell bank number, ???
0x202:   3, 12, 4, 12, 1, 12, 7, 10    ???, cell voltage, ???, cell voltage, ???, cell voltage, cell bank number, ???
0x204:   3, 12, 4, 12, 1, 12, 7, 10    ???, cell voltage, ???, cell voltage, ???, cell voltage, cell bank number, ???
0x206:   3, 12, 4, 12, 1, 12, 7, 10    ???, cell voltage, ???, cell voltage, ???, cell voltage, cell bank number, ???
0x212:   13, 10, 8, 8                  charger HV current (/20), HV voltage (/2), LC current (/5), LV voltage (/10).   

=== Guessing ===
0x210:   12, 2, 10, 3, 12, 4, 19    pack voltage (/8), ???, main pack amps? (/10), ???, amperage again? (/20), ???, ???
0x264:   4, 12             	    ???, minutes since last full charge (/2)
0x304    8, 8, 8           	    ???, charge HV current (/20), ???
 
#52 ·
You've got that stuff down. There's a few other things in that log that I should be able to finalize this weekend. There is a coolant temp in and out of the pack as well as the average cell temp of the pack. You can see the individual temps on the 125k bus between the BECM and BICMs. I might get time to connect the HPCM2 and see what it does this weekend, but I've been pretty busy with other things so no guarantee!
 
#54 ·
So I discovered that the HPCM2 isn't necessary in order to get the cell voltages out of a standalone Volt battery. You just to hook up to the bottom connector of the BECM module inside (K16 connector X1), with the following pins. If you're looking at the factory connector, numbering starts in the top right and moves left, they are the these colours:

1 - Black - Ground
2 - Red - 12V
3 - White/Black - CAN_Low
4 - Light Blue - CAN_High
9 - Black - Ground
14 - Brown/Red - 12V
15 - Orange/Yellow - 12V
16 - Light Green/Light Blue - 12V

This sets the Accessory Wake-Up Serial and Communication Enable lines high, and causes the exact same data you sent me in the log file to get thrown out the CAN lines on 3 and 4. That's all I need for this project (Solar Install) for now, but it would be awesome if someone could catch the battery balance command in the act from the HPCM2 (maybe by drawing down one cell while capturing the CAN traffic).

For now I am going to just build a system to let me see the cell voltages and alert me if any drop out of spec, then I'll go in and manually balance the cells.
 
#55 ·
Anymouse said:
So I discovered that the HPCM2 isn't necessary in order to get the cell voltages out of a standalone Volt battery. You just to hook up to the bottom connector of the BECM module inside (K16 connector X1), with the following pins. If you're looking at the factory connector, numbering starts in the top right and moves left, they are the these colours:

1 - Black - Ground
2 - Red - 12V
3 - White/Black - CAN_Low
4 - Light Blue - CAN_High
9 - Black - Ground
14 - Brown/Red - 12V
15 - Orange/Yellow - 12V
16 - Light Green/Light Blue - 12V

This sets the Accessory Wake-Up Serial and Communication Enable lines high, and causes the exact same data you sent me in the log file to get thrown out the CAN lines on 3 and 4. That's all I need for this project (Solar Install) for now, but it would be awesome if someone could catch the battery balance command in the act from the HPCM2 (maybe by drawing down one cell while capturing the CAN traffic).

For now I am going to just build a system to let me see the cell voltages and alert me if any drop out of spec, then I'll go in and manually balance the cells.
Click to expand...
I still haven't messed with the HPCM2... Cells out of balance is probably a pretty rare occurrence, but I had 3 cell groups that were really low in one pack, so it would have been a good time to test.
 
#56 ·
I wonder if it would be possible to move all of the components from a totaled Volt into a donor vehicle (if the motor and batteries work)? As long as it can mate to the transmission or drive shaft, it should work.
 
#58 ·
Hi All,

Could anyone tell me which one of the relay that's in front of the battery that I can use for a LVD (low voltage disconnect) or HVD (high voltage disc) for my solar application?

I got the 2013 chevy volt battery for my solar application. For safety I would like to have a HVD between the solar panels and my charge controller, shutting off solar power to the charge controller incase of a runaway. 80volts at 30amps. For the LVD between inverter and battery is 48volts and max out at 250amps (but probably never be that much, more like 100amps.

Which relay can I use out of the battery?

thanks
 
#59 ·
Hi Jimmyaz

You will find two large contactors and three small ones
The Volt uses the two large ones at 390 v and about 300 amps - but they did not like me putting 1200 amps through them

The three small ones are used at 390 v - but only 10 amps or so

I would use the small ones on your 80v and the two big ones on your 250 amps
 
#60 ·
Duncan said:
Hi Jimmyaz

You will find two large contactors and three small ones
The Volt uses the two large ones at 390 v and about 300 amps - but they did not like me putting 1200 amps through them

The three small ones are used at 390 v - but only 10 amps or so

I would use the small ones on your 80v and the two big ones on your 250 amps
Click to expand...
Thanks

A couple of page back someone mention that the big contractor are only for one time use if switched under load it might burnt? I wonder if they can be use regularly at 48v and 100amps max?

Are they normally "open", close when 12v applied?

Another thing is I'm going to have to figure a way to COOL the battery in summer (110F in my garage when it's hot). Is it safe to use regular water in the battery instead of the cooling fluid that it came with? Any idea guys?
 
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