Car not working after HV traction pack swap

[Graham]

Hello EV loving colleagues

I have been driving an i-miev since July 2019, love it, unfortunately someone wrote it off in 2021!
Loved it so much I bought another identical one (AFAIK) and have been driving that until now.
Started seeing the turtle recently and it eventually resulted in the car being undrivable (unsafe) due to the very hilly area I live in, turtle mode could result in stopping completely in traffic on some of the hills/ramps encountered on my daily drive.
Luckily I did manage to buy my old crashed (unroadworthy) i-miev back from the insurers due to it only having 14500 miles on the clock.
So (you can see where this is going) I decided that a traction pack swap was the best idea. To solve the issue and get me back on the road ASAP. I need the car for school runs and work, both small journeys, round trip of approx 15 miles.
Back in 2013 I converted a Honda Beat into an EV and drove that as my daily driver for 2 years, so I was up for a pack swap and am quite used to working with HV traction batteries, been driving EVs around 11 years now, converted Honda Beat, Mia, Kia Soul EV, i-miev (crashed), i-miev (current), and most recently a Jag i-pace. We are a two car family so they are not all mine!

Anyway back to my issue, following the complete removal, swap of traction packs I am faced with a flashing fuel indicator (on LCD), red aux battery light, and orange service warning light, and no charge bars are shown at all! This is despite me knowing that the pack from my old car (14500 miles only) was in good condition. After using OBDLink with canion app I got the status of the newly fitted pack and it looks great 0.2v difference across all cells.

In desperation and after watching several tube vids on the subject I decided a full electronics swap between packs was the best chance of success, maybe the electronics in the car was somehow coded to the traction pack, or just incompatible, anyway after meticulously swapping every BMS board on every cell pack and swapping the complete electronics sets between packs and refitting to test I am still in exactly the same place, no charge bars, flashing fuel LCD, red batt light, orange service light!

What am I doing wrong here?

I have today managed to get carscanner app working with OBDLink dongle and can now read/clear diag codes. But still no progress, currently disconnected 12v battery to see if this helps.

Car scanner initially showed 45 (historical) errors, after clearing all and rereading it now shows 15

U11AB 0xD1AB
U11AA 0xD1AA
U11A9 0xD1A9
U11A8 0xD1A8
U11A7 0xD1A7
U11A6 0xD1A6
U11A5 0xD1A5
U11A4 0xD1A4
U11A3 0xD1A3
U11A2 0xD1A2
U11A1 0xD1A1
U11A0 0xD1A0
P1AAB 0x1AAB

The last one seems to have something to do with HV interlock?

VIN numbers are JMALDHA3WBU000217 for the old crashed donar car and JMALDHA3WBU000297 for the car I am trying to fix.

Can anyone suggest what to try next? 12v battery was @ 12.2v (connected with car on) so I tried a second 12v battery slaved using jumper cables and this then boosted it to 12.5v (read from OBDzero I think) is this high enough? Still no change. HELP!

Do I need a scan tool of some type? To perform some sort of reset or commissioning? If so does anyone know a good choice for the i-miev?

 

[MickeyS70]

Hi Graham, welcome to the forum.

The symptoms and DTCs point to a CAN issue (CMU timeout) but you seem to be able to read cell voltages (all 88?) with CanIOn and Carscanner?

I would therefore suspect an issue with the BMU itself, did you try swapping it?

[Edit:] Re-read your post, 200mV across the cells is about 10 fold of a spread I would consider good balancing, what voltage is your highest/lowest cell?

Mickey

 

[michael8554]

12V Aux Battery volts should jump to 14.5ish when the car is ON.

 

[MickeyS70]

12V Aux Battery volts should jump to 14.5ish when the car is ON.

Correct, but I’m doubtful that’s happening in this case with the car not ‘seeing’ any CMUs.
I think because of this issue, the HV contactors won’t close and therefore the DC/DC converter doesn’t start, thus leaving the 12V aux do all the ‘heavy lifting’.

@Graham I know you have ‘slaved’ a second battery to your aux but the fact that you had to do this in the first place might point to a weak 12V (which is known to cause all sorts of strange problems).

Best to charge it overnight (or replace it altogether if it’s more than 3 years old) before continuing troubleshooting and measure voltage with ‘load’ (full lights, blower etc) afterwards.

 

[piev]

I agree with Mickey.​

Mitsubishi Service Manual​

Code No. P1AAB: Numbers Of Cells Abnormal​

CorrectionSorry the 2012 manual has a bad link. Here is the one to 2013.)

 

[kiev]

The symptoms and DTCs point to a CAN issue (CMU timeout) but you seem to be able to read cell voltages (all 88?) with CanIOn and Carscanner?

He did that before swapping out all the boards, etc. Not able to read anymore after that.

 

[MickeyS70]

He did that before swapping out all the boards, etc. Not able to read anymore after that.

Maybe one of CMUs is pulling down the whole secondary CAN bus? A quick way to verify is to measure the CAN bus resistance:

http://mmc-manuals.ru/manuals/i-miev/online/Service_Manual/2013/54/html/M154830010046702ENG.HTM

 

[Graham]

Hi Graham, welcome to the forum.

The symptoms and DTCs point to a CAN issue (CMU timeout) but you seem to be able to read cell voltages (all 88?) with CanIOn and Carscanner?

I would therefore suspect an issue with the BMU itself, did you try swapping it?

[Edit:] Re-read your post, 200mV across the cells is about 10 fold of a spread I would consider good balancing, what voltage is your highest/lowest cell?

Mickey

Hi Mickey
Thanks for replying so promptly, sorry had to take a break from the i-miev and pull my head out of the rabbit hole so to speak, try and step back, take a look outside the box. After spending the last few days getting my head around OBD dongles apps and the like I discovered that caniOn is not working and crashes immediately after connecting, the data I thought I was seeing was dummy example data, so you can ignore my 0.2v across all cells,

I have managed to get car scanner and OBDzero working they both connect and seem to pull data but I am no expert at reading CANbus data. CarScanner reports that all 88 cells are at 2.51v which I think means empty.

Tried to charge using granny charger but it won’t charge with the ignition turned off, as it usually does, when I turn ignition on the flashing charge light illuminates/flashes but I don’t think it is charging the HV pack, all cells still at 2.51v.

Where is the BMU? If it is inside the HV pack I have already tried this, if it’s in the car where do I find it?

Are there any fuses I should check? I may have forgotten to disconnect the 12v before pulling the HV cutoff (under seat), once or twice, would this blow fuse or cause the HV pack to refuse to be charged or not talk to the car?

I did also have problems disconnecting one of the 4 connectors (the black one) when removing the bad pack and sightless broke the surrounding plastic on the “good” car side The plug itself seems fine though so don’t think this should affect continuity.

I was baffled as to how the entire pack could have got flattened on the crashed donar car (assuming carscanner is right about 2.51v on all cells) but I stupidly left the 12v (dying/now dead) battery connected, could this drain the entire HV pack down? It fit sit unused for 2 years! It was left at half charge when I parked it up for storage.

Can carscanner or OBDzero do any sort of resets to fix this or is it more likely a hardware issue?

Bear in mind that I already switched the entire bms board and central electronics set from the original pack into the donar pack so the only change is the cells and the tray.

 

[Graham]

Correct, but I’m doubtful that’s happening in this case with the car not ‘seeing’ any CMUs.
I think because of this issue, the HV contactors won’t close and therefore the DC/DC converter doesn’t start, thus leaving the 12V aux do all the ‘heavy lifting’.

@Graham I know you have ‘slaved’ a second battery to your aux but the fact that you had to do this in the first place might point to a weak 12V (which is known to cause all sorts of strange problems).

Best to charge it overnight (or replace it altogether if it’s more than 3 years old) before continuing troubleshooting and measure voltage with ‘load’ (full lights, blower etc) afterwards.

Hi again Mickey
Yes the 12v battery is not good wont hold charge, however I have tried using a better battery with jump leads and a supporting charger, and car scanner reports 13.8 -14v with battery connected and 12v charger running at 12 amps, but still it won’t charge, if carscanner is correct I am guessing the pack is completely flat and needs a good charge, not sure if this is related, but it would explain the flashing battery lcd and no charge bars. I am in process of sourcing new 12v battery, although I don’t think this will solve it alone.

 

[Graham]

Maybe one of CMUs is pulling down the whole secondary CAN bus? A quick way to verify is to measure the CAN bus resistance:

http://mmc-manuals.ru/manuals/i-miev/online/Service_Manual/2013/54/html/M154830010046702ENG.HTM

CMUs? Are these in the HV pack and what does CMU stand for?

One of the DTCs definitely said something about HV interlock, what does this mean? I will try and clear and read some more DTCs today and see if that one is still showing.

 

[Graham]

Oh I should also mention that I could not get one of the white retaining clips to slide back into the locked position, would this cause an issue? Are the white clips on the orange connectors near front of pack doing anything electrical? I think they are just mechanical retainers, but the HV plugs did click into place, also tried contact cleaner on all traction pack signal connectors and HV plugs.

 

[kiev]

I may have forgotten to disconnect the 12v before pulling the HV cutoff (under seat), once or twice, would this blow fuse or cause the HV pack to refuse to be charged or not talk to the car?

Yes that would throw a code that i think requires a MUT tool (dealer) to clear. But someone who has dealt with that code would know more.

Are the white clips on the orange connectors near front of pack doing anything electrical?

Yes again if you can't easily slide those in place then start over because something is jammed into the wrong hole or slot. The HV Interlock consists of 2 tiny pins for an electrical signal betwen the 2 sides of the HV connectors.

Maybe you could read up in the manual to understand how all this works and is connected, names of items, how to disconnect and connect HV cables, etc. You have jumped way into the deep end and don't seem to understand some of the basics--you are a little bit scary here with the ready, fire, aim approach.

 

[MickeyS70]

I have managed to get car scanner and OBDzero working they both connect and seem to pull data but I am no expert at reading CANbus data. CarScanner reports that all 88 cells are at 2.51v which I think means empty.

Not necessarily, the Cell Monitoring Units (CMUs) transmit cell voltages as hex and OBDZero/CarScanner use a formula to ‘translate’ it into a decimal number, a zero or no data value would be displayed as 2.5V.

Pity you didn’t actually measure the cell voltages when you had the pack open, but then again hindsight is 20:20.

Tried to charge using granny charger but it won’t charge with the ignition turned off, as it usually does, when I turn ignition on the flashing charge light illuminates/flashes but I don’t think it is charging the HV pack, all cells still at 2.51v.

The DCTs point to a CAN issue and charging will be disabled

Where is the BMU? If it is inside the HV pack I have already tried this, if it’s in the car where do I find it?

That depends how old your car is, in older models (pre 2015?) the BMU is under the seat bench, however a depleted 12V aux might have wiped the current settings and swapping it in this stage may create more issues

Are there any fuses I should check? I may have forgotten to disconnect the 12v before pulling the HV cutoff (under seat), once or twice, would this blow fuse or cause the HV pack to refuse to be charged or not talk to the car?

A known cause of ‘zero’s being transmitted is a blown SMD fuse on the CMU board, don’t think pulling the HV service plug will blow all 88 of them, twice??

I did also have problems disconnecting one of the 4 connectors (the black one) when removing the bad pack and sightless broke the surrounding plastic on the “good” car side The plug itself seems fine though so don’t think this should affect continuity.

If it’s the one used for the CAN bus (see post #5 C26) then this may explain things,

I was baffled as to how the entire pack could have got flattened on the crashed donar car (assuming carscanner is right about 2.51v on all cells) but I stupidly left the 12v (dying/now dead) battery connected, could this drain the entire HV pack down? It fit sit unused for 2 years! It was left at half charge when I parked it up for storage.

Still convinced (until proven otherwise) that the cells are actually OK

Can carscanner or OBDzero do any sort of resets to fix this or is it more likely a hardware issue?

I would put money on a HW issue (cable loom)

Bear in mind that I already switched the entire bms board and central electronics set from the original pack into the donar pack so the only change is the cells and the tray.

.. at what stage did you damage the data connector on the good car side?

I am in process of sourcing new 12v battery, although I don’t think this will solve it alone.

Agreed, but this will definitely pay off in the long run

I will try and clear and read some more DTCs today and see if that one is still showing.

Maybe get your 12V aux sorted first, while you’re waiting do as @kiev suggested, then measure the resistance on the battery CAN bus (link in post #10). first on the pack side, then from the BMU (to rule in/out broken connector)…

Mickey

 

[Gary12345]

Probably there are 80 cells in one pack and 88 cells in the other, and you didnt move the BMS from under the back seat so the car can't talk to the new pack. 2.51v is the default when no data is received. The BMS wont have been wiped, etc, thats a rumour but hasnt even been shown to actually happen. I've bought cars that have been sat for years, fixed the faults and they fired up. Even if BMS data was forgotten, its just capacity stuff that it can relearn.

You really need a better diagnostic tool so you can have a description for the fault codes. See my comparison of diagnostic tools here.

 

[MickeyS70]

Probably there are 80 cells in one pack and 88 cells in the other

I think @Graham would have noticed the difference, besides both are I-Mievs, see VIN in OP?

 

[Graham]

Yes that would throw a code that i think requires a MUT tool (dealer) to clear. But someone who has dealt with that code would know more.



Yes again if you can't easily slide those in place then start over because something is jammed into the wrong hole or slot. The HV Interlock consists of 2 tiny pins for an electrical signal betwen the 2 sides of the HV connectors.

Maybe you could read up in the manual to understand how all this works and is connected, names of items, how to disconnect and connect HV cables, etc. You have jumped way into the deep end and don't seem to understand some of the basics--you are a little bit scary here with the ready, fire, aim approach.

Hi Kiev

Thanks for posting. Guessed as much, I knew I had made a mistake as soon as I realised, I had forgotten to disconnect the 12v when pulling the HV disconnect plug (remembered it 1st time removing the pack from the donar car, but forgot this step on the 2nd removal from my "good" car), had a bad feeling I was going to need a car scanner to rectify this, I think you and Gary have now confirmed this.

The white lugs I was referring to are on the two HV cables that connect the pack to the car at the front of the pack (not inside the car under the seat) AFAIK these are just mechanical retainers and don’t have any electrical (interlock) significance, however just to be sure I have managed to get them in place today as I am hopeful that I shouldn't need to remove the pack again to get this car on the road. Surprised to find that the i-miev service manuals are available to us mortals (not so in 2017 for my beloved MIA ☹), although I would generally refer to them when needed rather than read them end to end before staring the job, in true Haynes manual style.

But you are correct. RTFM! My bad. I could have avoided the need for a garage spec scanner if I had removed the 12v aux batt entirely and put it away in safe place until I was ready to test, DOH! Still, you live and learn, and I have two other EVs to repair/recommission when time allows, a Kia Soul EV (love/d this car) and a MIA (Love/d this one also) bit of an EV nut, but this is my first go at working on my consumer EVs.

I was trained on building a HV traction pack by Jozzer (JozzTech) of DIYElectriccar fame back in 2013, he once said to me “it’s like building a bomb” so I am fully aware of the risks involved when opening a traction battery. High currents and Voltages can be lethal if not respected.

I worked my round the pack one step at a time replacing every nut and cover before moving onto the next, using gloves and one hand only when touching metal contacts to avoid any potential for electrocution, so please don’t worry.

I am also guilty of the “Ready! Aim! Fire!” approach, due mainly to me needing this car on the road ASAP, and limited time to work on it, I have spent most of my annual leave for this year working on it and didn’t have much time to hang about and contemplate things.

Still I should have come here first!

 

[kiev]

i was thinking the cell voltage of 2.10 is the indication of a "zero" or no signal, based upon the PID calculation?

 

[kiev]

so I am fully aware of the risks involved when opening a traction battery.

Okay that is good to hear and a relief, we never know the skill level on the other end of a forum conversation.

 

[Graham]

Not necessarily, the Cell Monitoring Units (CMUs) transmit cell voltages as hex and OBDZero/CarScanner use a formula to ‘translate’ it into a decimal number, a zero or no data value would be displayed as 2.5V.

Hi Mickey, thaks for following up. Ahh, that makes sense.

Pity you didn’t actually measure the cell voltages when you had the pack open, but then again hindsight is 20:20.

Yeah, kicking myself for this now, but didnt want to poke around any more than I had to.

The DCTs point to a CAN issue and charging will be disabled

Right! Got it!

That depends how old your car is, in older models (pre 2015?) the BMU is under the seat bench, however a depleted 12V aux might have wiped the current settings and swapping it in this stage may create more issues

Both the donar and the driver are older than 2015 and there is a big lump under the carpet on drivers seat in both cars which sort of confirms this. Do you access the BMU (if needed) from inside the car or under the car?

A known cause of ‘zero’s being transmitted is a blown SMD fuse on the CMU board, don’t think pulling the HV service plug will blow all 88 of them, twice??

I guess not.

If it’s the one used for the CAN bus (see post #5 C26) then this may explain things,

Yes, but I have double checked the connections and they all look fine, no bent or broken pins, (cleaned with contact cleaner) and I have also essentially tested both looms in the HV packs so if there is an issue here it must be on the car side, the slight plug damage was only to the external shroud (car side) and shouldn't affect continuity of the low voltage signals, could this condition be just caused my the need for a reset from a car scanner? I could swap the CANBUS loom from the donar car, this might solve it, if it is a hardware (cable loom/connector) issue. I am getting close to trying this but wonder if I should wait until I have a new 12v Aux battery in place and an Autel car scanner for the (looking like required) reset/s.

Still convinced (until proven otherwise) that the cells are actually OK

Agreed, I am sure the pack is good. It was from a crashed car (I was in it) but I drove it home after the crash and charged it subsequently and it drove true and worked fine, written off due to sub/main/frame damage (Bummer!)

I would put money on a HW issue (cable loom)

You may well be right here, so close to stripping the can loom from the donar.

.. at what stage did you damage the data connector on the good car side?

Car side, but as I said it was just the exterior clip shroud, no pins have been compromised, that said it was very difficault to remove in the first place (unilke the donar) which could point to corrosion. The pins look grey not shiney and so could be oxidised and not making good contact.

Agreed, but this will definitely pay off in the long run


Maybe get your 12V aux sorted first, while you’re waiting do as @kiev suggested, then measure the resistance on the battery CAN bus (link in post #10). first on the pack side, then from the BMU (to rule in/out broken connector)…

Mickey

Will do. Aux batt first, Then source a decent Autel scanner, one that can do the interlock reset (will ask Gary what model he uses) and take it from there if that does not cure it I will prob pull the can loom from the donar to solve the broken shroud on the canbus connector, and if it still wont play ball try swapping the BMU in from the donar car. Does that sound like a sensible plan of action?

 

[Graham]

Probably there are 80 cells in one pack and 88 cells in the other, and you didnt move the BMS from under the back seat so the car can't talk to the new pack. 2.51v is the default when no data is received. The BMS wont have been wiped, etc, thats a rumour but hasnt even been shown to actually happen. I've bought cars that have been sat for years, fixed the faults and they fired up. Even if BMS data was forgotten, its just capacity stuff that it can relearn.

You really need a better diagnostic tool so you can have a description for the fault codes. See my comparison of diagnostic tools here.

Hi Gary, thanks for posting, and also for posting great YouTube videos, I only just found you on YouTube and just in the nick of time, you seem to be going thorugh another i-miev repair right now and are looking to source some/a charging/balancing board/s, I may be able to help here as I have my crashed :-( donar car and wont be needing all the (BMS/CMU?) boards, I can't see myself repairing loads of i-mievs but I am wanting to keep mine on the road as long as possible so will hang onto some of them, not sure if you can do PM's on here but happy to make contact however you prefer to discuss.

Watched your video with interest, the i-miev you are repairing now is exhibiting exactly the same fault lights on the dash as mine (allbeit a different fault) you say in this video that the Autel "will be needed to fix this car", I need a fully featured scanner now to fix mine, and I also have other EVs in need of attention (Kia Soul Ev and Mia) can you tell me the exact model of Autel you are using have used to perform HV interlock resets on i-miev's?

I stupidly forgot to diconnect the 12v batt during the pull off the battery from my good car under repair and this seems to have bricked the car requiring a reset DOH! I am guessing from your video that the cheaper scanner you show wont do all this and I likely need the "garage spec" (your quote) scanner to do this. I see that there is a very wide range of Autel scanners out there £300-<£1000, dont want to waste money, but would like to find one that can do the i-miev resets at least and the Kia Soul EVs if possible, if it can talk to the Mia I would be amazed (is there a profile for yours for a Mia?) if so I would just love to get the Mia back on the road (we all love/d that car) at some point.

Cheers, Graham.