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Discussion Starter #1
retepsnikrep has said that if enough interest in the community exists for CAN bus LTO cell monitoring he would pursue the necessary software. LTO blocks need to be daisy chained together, then a twisted pair of wires from the LTO battery blocks (LTO CANH & CANL) will need to be routed to the OBDII socket.

His software mod, plus a CAN modified OBDIIC&C to be used as normal, would be capable of LTO pack monitoring. A $1.50 CAN Communicate Protocol Controller Bus Interface Module MCP2551 High Speed CAN Communicate Protocol Controller Bus Interface Module | eBay is a typical board that needs to be installed into the OBD2C&C. This allows the CAN board to talk to the blocks to get the ID's and cell voltages etc.

The software could provide audible/visible alarms, etc. based on high/low LTO cell voltages.
Voltage checks are performed once a second. For now I have set the alarms at 2.65V as cell max. and 2.00V as cell min.

This new LTO CAN mode will likely be a simple menu/mode option in the normal OBDIIC&C firmware. Nothing exciting and no more difficult to select than any of the other standard OBDIIC&C stuff. All of the above wording came from retepsnikrep’s thread OBDIIC&C LTO BMS CAN INTERFACE

I have purchased a full, 24 pack Honda Fit Sensor harness that is used to daisy-chain the packs we have. I will split this harness to useable three-pack harnesses (six plugs that attach to the pig-tail cable that in-turn attached to the LTO sensor board) that would perform the above tasks, assuming retepsnikrep completes the software. The cost would be $15 per 3-pack harness plus $5 S&H. I can only make 5 harnesses to sell.

It will take me some time to understand how to separate this huge harness but it will be done professionally and include the connectors.

If interested please send me a Conversation. I can only accept the first 5 people.
 

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Discussion Starter #3
It's possible but for me to break even money-wise I counted on selling five harnesses with six connectors. What I can do is charge you for nine connectors. That would leave you four extra, unused connectors, enough for two packs. If one of the first five people wants a two-pack (four connectors) that would automatically work everything out. Shake the dice or sell two yourself.
 

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Thanks, thinking about it I have no problem paying $30 for two harnesses to help you break even since I need to that extra connector. I'm lucky to have a decent paying job now so not a big deal for me.
I'll see if anyone else wants to split with me.

I think there should be others who may want 7 or 8 connections just in case they decide to use more than 6 packs, like 7 packs or 8 packs. I see nothing wrong with just having a spare connector or two there for future upgradabiity. Maybe I will upgrade to 8 packs.

So you can put me down for 2 or 1.5 depending on what other people order.

Thanks. Getting these packs BMS working is really a great thing.
 

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I would definitely be interested in a harness for a 6 block 72 cell configuration.. I spent a while trying to source the connectors on the harness but was unable to come up with anything so this would be awesome. I plan on using this with the BCM Replacer. How do you plan on dealing with the distribution of the 6 and 8 pin connectors ?
 

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I think this just amounts to a change of the short pigtail between the board and the harness. Both plugs carry the essential wiring of the BMS, the extra two wires on the rare few blocks carrying the temperature probe wires. Since the temperature sensors are fairly rare, the 8 pin plug will be also. If you have one, you should be able to swap someone for an 6 pin pigtail. Ideally everyone should have temperature sensors and 8 pin plugs on ALL their blocks but this is highly unlikely given the minimal # of such sensors.

I don't think we even understand how the temperature circuit would have originally worked. Since there are apparently only two wires in the harness devoted to all of the probes in the Fit, the probes must have been in series. We don't have the computer they plugged in to, so making them functional is a separate engineering job.

I just redistributed and installed the 4 temp sensors from the Insight OEM pack to monitor temperatue of the pack. Apparently the Interceptor functions to provide measurement on the OBDII C&C about some nominal threshold - forget the threshold. The newer BCM replacer may provide direct temperature reading of each probe. I forget what was discussed in that development thread.

Short answer I guess, maybe John can mix and match the owners requirements to some degree, but seems like no guarantee of that given the strange combinations. Pigtail swaps probably more likely.
 

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Discussion Starter #7
@(Peter) I got this huge harness sorted-out today so I know where the In's and Outs are. I hope someone can answer my questions about the different large connectors connected.
- What are the five 'Buss connectors"? There are a bunch of wires going into a dead-end connector and it appears as though everything going-in is connected together
  • There are two 33-pin connectors that have two holes on each where they get bolted into chassis somewhere;
  • There's a 23-pin connector that has a mechanical locking mechanism
  • There's a two-connector thingy that only has wires going to one side.
Tomorrow I will be unwrapping the plastic sheathing and trying to sort-out a good way to make six three-pack harnesses. I'm not sure if the above connectors are important or if I can cut them out altogether. I'd appreciate your best guesses.
Harness Tree.jpg
 

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John. Can you post a seperate picture of each connector then I can examine the remnant of my harness and respond.
I want to make sure we are talking about the same ones etc. My harness is already chopped up.
 

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Discussion Starter #9
20200304_103124.jpg 20200304_103148.jpg 1) same plug, two views

20200304_103212.jpg 20200304_103224.jpg 2) same plug, two views

20200304_103241.jpg 20200304_103434.jpg 3) same plug. There are five of these. Looks like wires are consolidated in here then go out again. Is this because some runs are too long for good conductivity

20200304_103523.jpg 4) pretty hefty. These apparently get bolted to the chassis.

Plugs 1 and 2 are at one end and close to each other.
 

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I can't tell you much.

FWIW it doesn't matter anyway as you are going to be breaking the harness apart and just using the block connectors and basically making your own harness.

1,2,4 no idea really, and as above it doesn't matter anyway.

3 are common connection points. Common ground/negative (black) and probably common power/positive (red)

You will be just be making a CAN daisy chain harness with a 120R termination resistor on the final block farthest from the OBDIIC&C/BCM Replacer.
 

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Discussion Starter #11
@Peter
Just discovered that the one male sensor-board pigtail with the additional green female four-pin (two wires) connector has eight connections. None of my other male pigtails have the green connector, nor do they have eight pin connections. I also discovered that female plugs #1, 7, 20, 22, 23 have 8 pin receptacles and female connector #26 has two pin receptacles. This has got to do with CAN bus communications.
 

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I ain't Peter, but... The 8 pin pigtail is the one that is used with the occasional block having a temperature probe. The 6 pin pigtail is the one which is used with all the non temp probe blocks. I don't remember what I gave you. Non of this harness wiring was of use when we made the exchange.

I ordered a harness of my own, but not sure I'll ever use it.;)
 

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Discussion Starter #13
I was more interested in the female plugs #1, 7, 20, 22, 23 and and female connector #26.

I'll send you all my information when I figure it out. Sure is a PITA and time consuming when one doesn't have an automated assembly line.
 

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You have to be very careful with colour coding. Make spreadsheet or copious notes.

IIRC The pigtails that actually go into the blocks and plug into the LTO bms board under the cover have different wire colours to the connector that plugs into it at the other end.

I suggest just cut the number and type of harness connectors you need off the oem bundle with at least six inches of attached wire then make your own harness..

This diagram shows a basic CAN bus daisy chain setup. It might help clear up what is needed.
For simplicity I haven't shown the 12V power and ground for each block which also need to be connected.
Ignore the pin numbers etc I downloaded the diagram from the internet.

Forgetting about the temp sensor for now. Each LTO pigtail needs six wires.

CAN H IN
CAN H OUT
CAN L IN
CAN L OUT
12V+
GND

84662
 

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Discussion Starter #15
I'm aware of everything you've mentioned. I do have copious notes. It'd be interested in the answer to my original question of the specific connectors, and I understand you probably don't know
 

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Discussion Starter #16
Can I assume that all Red and Black wires within the harness don't get connected to anything since they power the Sensor Circuit board which is not being used? Do you see any future possibility for powering this board?
 

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The sensor circuit board?

The LTO BMS boards needs power not just the CAN H & L lines.
They all need +12V and GND (Red & Black)
 

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Starting to get the OBDIIC&C sorted now for the LTO connections and sorting out my LTO harness etc.
I want it to all remain as plug and play as possible.

I have finished two CAN enabled OBDIIC&C devices. I will be adding three extra wires to the OEM OBDII Socket.

1) CAN H Pin 10
2) CAN L Pin 11
3) Relay Control Pin 8

I'll run these extra wires back to the IPU for connection as required.
The CAN wires will be a twisted pair.

 
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