Yes, both mine (donar/driver) have 88 cells, both have the two half sized blocks in the middle.
Car not working after HV traction pack swap
- Thread starter Graham
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You’re correct, (as per usual), I should have looked up the formula rather than relied on my memory (will I ever learn?)
cell_Voltage=(MSB * 256 + LSB) / 200 + 2.1V
Unfortunately that means that the 2.51V reported could be a true representation of the HV pack and that requires a completely different approach.
I also checked the HV shutdown schematics, pulling the service plug while the car is off but 12V connected seems no different to ‘turning’ on the car with it out, pretty sure I did that myself, it sets a DTC but that disappears once you reconnect it?
What @Gary12345 mentioned in his video is to re-ID the CMU boards, should not be necessary here as @Graham swapped them ‘like for like’ and order shouldn’t matter anyway as @alviseven proved just recently.
Imho the only way to get somewhere fast now is to drop the pack and measure the cells, if they are low they need to bench charged, if they are fine one can test/swap CAN loom?
Ahh, is 2.51v too low for the pack to be charged via the charge port on the car? I do have the kit required to bench charge and balance all cells identical if required, had to do this twice before with my DIY build Honda beat conversion. Was not banking on this though.
Am I correct in thinking a bad 12v aux battery could potentially drain the entire pack this low in a year or so? I guess it could, but still surprised the car won’t allow charge from 2.51v, but then I guess these cells may have a bottom limit of 2.50v and maybe the BMU/CMU cuts off at this point to avoid cell destruction? Still not sure if I will need a good scanner to solve this or do you think if I get all cells up to say 3.7v (half charge) the BMS/CMS will allow charging without a reset?
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Yes, that is correct. The equation can be found on the forum.
Good to have the equipment/knowledge in case you need it.
I don’t think so, although iirc there was an instance where someone literally buried a pack for solar storage, left it untouched for a year or so and then discovered it was completely flat, got it back in the end though.
The cell operating limits are 2.75V to 4.1V. From people experimenting with NMC cells we know the car stops driving outside these limits, so my ‘educated guess’ would be that it also prevents charging.
Once you’ve above 3V DC/cell you should be good to go, make sure balancing is <20mV
But it’s still not clear to me what the actual issue is, the DTCs point to a CAN problem while the OBD readings show a flat HV pack. Without verified CAN bus operations you have no idea if the data received is accurate.
Incidentally this data is routed through the BMU (it’s located under the passenger seat bench). Which brings me back to my original hunch. After you check the CAN bus for shorts to 12V/GND you could swap it, might save you the next step:
Drop the HV pack and measure overall pack voltage, then module voltages (ten 8 blocks, two 4 block) maybe open a 4 cell module to verify individual cells and post your findings.
Hi again Mickey
Ok pack dropped this morning, measured all cells on one block and they are all at 3.9v, although this does not explain the fault, at least the pack is still where I left it and still in good shape and I can safely say that a dead 12v battery does not deplete the HV pack, I guess this leads me onto checking/testing/swapping the CAN loom next.
This might be a clue to the issue of not having CAN communication,
This would suggest to do a continuity check of the CAN buss wiring harness from the Pack to the BMU.
This would suggest to do a continuity check of the CAN buss wiring harness from the Pack to the BMU.
Good to know that the cells in one module are OK. To prevent another ‘I wish I had’ moment I would recommend to measure the voltage of all 88 cells and keep a record, if there are outliers now is the time to bench balance them.
To go back to your CAN issues, did you ever get ODBZero to read out cell voltages and temperatures?
After doing the basic continuity check as @kiev suggested I would disconnect all but one CAN connector on the modules and with just the data cables connected read out cell data with OBDZero, if successful add another one and so forth…
Progress at last, after taking a very close look at the low voltage connections to the traction pack I discovered that the CAN connector does indeed have an interlocking mechanism built into the connector and where I had damaged the connector shroud during removal revealed a very small white square, this was the end of a sliding plastic bar that is clicked/toggled into the closed position when the connector it pushed home, this was not happening due to the missing piece of plastic shroud, the solution was simply to push the small white plastic square (the visible end of the interlock bar) in about 2mm and “click” an audible click confirmed this was indeed an interlock switch built into the low voltage CAN connector, thanks to watching Gary’s latest video on YouTube I understood that it was not necessary to connect the high voltage connections on the traction pack in order to diagnose the CAN bus, so after figuring the CAN interlock, sliding the pack back under the car just enough to connect the low voltage connections and test I now have CAN comms with the pack and things we’re looking up, (so I thought), after connecting evaerythig back up and bolting the pack back in place and fitting the brand new 12v aux batt for a proper test the car now drives! However, the turtle fault is still present! This now leads me to believe that the problem may be with the DC-DC convertor. After giving both the traction pack and the new 12v aux batt a full charge and using the apps and OBD dongle I can now see the full pack and CAN comms seem to be working normally. I have 0.1v between cells so the pack is in great shape as expected. However, whilst testing the fault by attempting to drive the car I see that the aux voltage drops from 14.5 to 13.2 when the triangle warning 
appears, followed immediately by the aux batt light and then the turtle, I then re read the DTC codes cleared them ad read them again and I am now only seeing three DTCs U1116, U1111 & B1105, I do need to try this test again as I may have cleared codes and read these three before throwing the turtle fault. Sorry for the long post and delay in replying but iI have been back at work this week and it has not stopped raining since Sunday last week! can anyone tell me if the DC-DC converter is built into the BMU (under the seat on mine) or is it located somewhere else?
appears, followed immediately by the aux batt light and then the turtle, I then re read the DTC codes cleared them ad read them again and I am now only seeing three DTCs U1116, U1111 & B1105, I do need to try this test again as I may have cleared codes and read these three before throwing the turtle fault. Sorry for the long post and delay in replying but iI have been back at work this week and it has not stopped raining since Sunday last week! can anyone tell me if the DC-DC converter is built into the BMU (under the seat on mine) or is it located somewhere else?If you are reading 14.4 at the battery when the car is in READY, then the DCDC is working.
The DCDC is located in the bottom plenum of the OBC unit in the rear motor bay.
The B1105 DTC is related to the A/C Control Unit, which is located under the rear seat along with the BMU and EV-ECU and lots of wiring and connectors. That would be a good area to inspect for wiring damage or connector terminals corrosion.
The DCDC is located in the bottom plenum of the OBC unit in the rear motor bay.
The B1105 DTC is related to the A/C Control Unit, which is located under the rear seat along with the BMU and EV-ECU and lots of wiring and connectors. That would be a good area to inspect for wiring damage or connector terminals corrosion.
Well done spotting this..
Where do you ‘see’ that? Did you measure across the battery terminals?However, whilst testing the fault by attempting to drive the car I see that the aux voltage drops from 14.5 to 13.2 when the triangle warning
Ignore U1111 & U1116, (unless you have one of them remote controls). As @kiev mentioned B1105 is to do with AC and that shouldn’t trigger the tortoise.
You’re right, I would also expect additional DCTs (Pxxxx) when the fault occurs.
http://mmc-manuals.ru/manuals/i-miev/online/Service_Manual/2013/55/html/M155010070001901ENG.HTM
Hi Mike
Thanks again for the prompt and helpful response, I have just completed another round of app OBD testing and feel I may finally be getting to the root cause of the issue (or an issue at least). I started by connecting OBD dongle turning on (not drive) and using car scanner to clear and re read DTCs, same three code shown no warning
at this point, then after simply switching to drive/ready and then cycling through the gears, not pressing accelerator at any point, after several cycles through the gears (I had also used some wd40 on the selector to free up the stiff gear linkage) the warning appears, could this be a faulty or failing gear selection sensor? After reading DTCs I now see P1A44 in addition to the other three, I have just found a Misti reference to P1A44 “gear leaver position sensor 7 circuit-low” is this the smoking gun? I also see non Misti references to ground faults under this code. Am I on the right track here? Would it be sensible to swap the gear selector switch from my donar car? I have always found the gear selection to be stiffer in this i-miev than my previous crash victim (donar) i-miev, and have not until very recently been able to select “C” for cruise mode, I usually drive in “B” mode anyway so this has never been an issue for me, but I am now wondering if this could be the root of my troubles.Hi Kiev
Thanks for replying so promptly, you guys must live on this forum ;-)
I was hoping it was not a DC-DC converter fault and after more testing this morning a P1A44 DTC seems to be the issue, so hopefully you are correct and the DC-DC converter is fine. It could be a faulty gear selector sensor, see my reply to Mike above for details. The air con has not been working for a while I noticed this at the start of this summer when I tried to use it to cool the hot cabin in hot weather and it was just blowing hot air, I am assuming that the gas has leaked probably need a new air con seal kit and re-gassing to solve this but I don’t think it’s related to the current fault. But I could be wrong here, I know from reading/watching tube vids (and a weird experience when I first bought the i-miev) that the air con is drawn through the traction battery during rapid charging, When I first bought the first i-miev I needed to use the rapid charge to get it home and when I came back to it after a good charge there was water literally running out from under the car, I thought the worst and suspected a leak but after taking it in to the Mitsi garage for a basic service,was told that this was simply waste water that had condensed and been dumped during rapid charging, apparently this is normal on a hot day (it was hot) when rapid charging. I think I will swap the gear selection sensor next and see if this resolves the P1A44 error. I have hardly used the rapid charger since owning both cars, twice in total I think, but if I can resolve the turtle and get back on the road I will probably fix it with a new seal kit and gas anyway as it is nice to have that option if needed.
Not sure where you found that reference but P1A44 is a “ground fault” DTC. While it could occur anywhere within the HV system, water/moisture inside the AC compressor is reported to be the most likely cause (happened to me also)
https://myimiev.com/threads/solved-p1a44-p1a45-isolation-ac-pump.4439/
Seeing that your AC isn’t working anyway, you could disconnect the HV cables to it, if the fault disappears, you have found your smoking gun…
Hi Mickey
Here is the Misti reference to possible gear lever position sensor issue,
[Mod Edit: this link is for PHEV, not valid for miev]
https://mitsubishitechinfo.com/data/DGE/2023/03/HTML/N503230670000700USA.htm
Unfortunately swapping the part in from the donar has not cured the issue, so I am now going to look at the AC compressor as my next line of enquiry.
I note that there dont appear to be any removal guides for this that I can find easily online, you suggest that all I would need to do is disconnect he HV cables to the AC compressor to resolve this, would this throw any other DTCs that I should expect?
And if water in the AC compressor electronics does turn out to be the issue, will disonnceting the HV cables to it be enough to solve the warning/turtle issue?
I would be happy to do this now just to get the car back on the road but would prefer to solve the problem by removal of the top cover and drying out the AC compressor electronics and resealing it, but as I said I cant seem to find any decent guide on where to start and I dont really want to have to drain the AC system either but I guess that you cant remove the top cover to the electronics AC compressor housing whilst in situ?
Graham
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That is a bad link for your car--it is for a PHEV, not the i-miev.
Here is the P1A44 for miev:
http://mmc-manuals.ru/manuals/i-miev/online/Service_Manual/2011/54/html/M154921280001600ENG.HTM
Check the online workshop manual, it’s called ‘compressor assembly’
Assuming it is the AC compressor causing the ground fault, removing the HV cable will stop the tortoise and power loss, but will flag other AC related codes, doesn’t stop you from driving though..
Yes
I managed to remove the top cover without draining it, there is enough slack in the hoses..
Thanks Mickey
That does seem to have done the trick, the car now drives, Hoorah! Unfortunately, it has thrown up another issue, although I am not seeing any more DTCs, it does now have the airbag warning light lit permanently which I guess will fail it’s MOT, tried clearing codes but this did not solve it. Would disconnecting the two HV cables to the AC compressor unit cause this? Can I solve this without fixing the AC compressor?
Strange, this was usually only happens if you connect 12V aux before the connectors under the driver/passenger seats. You can clear it with Hobdrive.
