I'm buying a non-runner MIEV here in Japan!

[kiev]

The reason to only jack up one side is to lock up the differential in the gearbox so that the rotation of the wheel will primarily back drive the motor rather than spin the wheel on the other side.

The spin direction doesn't really matter, just whichever is easier. Either side is fine too, i just figured the right rear would be easier to spin. The hard/easy sections of spinning may be due to brake drag if the rotors are rusty. Remove the right wheel and use a screwdriver to pry the pads away from the rotor (manually spread the pads)

The DTC check with the motor leads disconnected seems to indicate that maybe there is a shorted winding in the motor, or that one of the current sensors is defective, or the control board interpretation of the current sensor data is flawed. This was seen in one of your previous data captures showing current at 2000 Amps !? Was that the new or old MCU ?

Were you able to measure resistance between the motor phases, and between phases and chassis ground/motor housing? You can refer to them by color if that is easier, R, W, B.

 

[kiev]

Did you try turning a wheel while 2 phases were connected together (shorted phase test), and also with all 3 connected together?

 

[Rational]

The reason to only jack up one side is to lock up the differential in the gearbox so that the rotation of the wheel will primarily back drive the motor rather than spin the wheel on the other side.

Thanks for that clarification detail. The wheel on the other side doesn't spin when I spin the other side.

So I guess this means the test is still valid with both wheels off the ground?

Remove the right wheel and use a screwdriver to pry the pads away from the rotor (manually spread the pads)

Will do next.

This was seen in one of your previous data captures showing current at 2000 Amps !? Was that the new or old MCU ?

It was? Where did I post that showing current at 2000 amps? I guess I didn't know to even look for it to notice.

This is the new MCU but with the old/original controller board. I did this so the chassis number would match.

Were you able to measure resistance between the motor phases, and between phases and chassis ground/motor housing? You can refer to them by color if that is easier, R, W, B.

I will do that now. Do I just set it to ohms on the multimeter and see what it shows?

R,W,B is easier. Will do it that way from here on out.

 

[Rational]

Okay. Here is the i-miev motor UVW resistance test results video.

 

[kiev]

Just a post listing the resistance would be fine. The utube videos are not playing with message "Sign in to confirm you're not a bot"

There is a reason why i asked that you only turn the key to ON after clearing the codes, and then check which codes reappear without starting (looking at the U1111 CAN buss code). But finish all the phase testing first before putting it back together. i'm not really sure what could be learned or proven by starting without the motor connected? Putting the new control board back into the new MCU with the motor connected would be more useful to prove the IGBT code goes away, even if it throws an eeprom chassis error, that would be progress. Then the old eeprom could be desoldered and installed on the new board,

i'm hoping that spreading the brake pads on one side will free up the spinning wheel and you can capture some winding voltages while spinning. Maybe use a peak hold function on the meter while in AC volts (the output is a sine wave with + and - sections). If you could spin the wheel using a lug wrench or some tool to get maybe 1 rev per second, or per 2 or 3 seconds, however fast you can spin it. Just catch the peak hold at a certain speed, then write it down and do the other phases. If you can spin them all about the same, then compare the voltage readings--just looking if they are all about the same, or if one phase causes a lower reading. On the one video i could watch, the phone was moving too much to read the screen, that's why i suggest using peak hold feature, or min max, if your meter has such.

 

[Rational]

There is a reason why i asked that you only turn the key to ON after clearing the codes, and then check which codes reappear without starting

When you say "ON" you mean ACC? Which I believe is the half position before full start up? I just want to make sure we define our terms before I misspeak.

So far when the ignition is in the half position before full start position it does not read DTC codes nor talk to the car. No codes can be obtained unless I have the car fully turned on and showing START on the dash.

i'm not really sure what could be learned or proven by starting without the motor connected?

I thought you or Mickey had said this would tell us something if no P1A2A codes appeared again with the motor disconnected.

Putting the new control board back into the new MCU with the motor connected would be more useful to prove the IGBT code goes away, even if it throws an eeprom chassis error, that would be progress.

II will do that once I take the right rear wheel off and spread the break pad away from the rotor and try to get further resistance tests with the multimeter set to peak hold if I can figure that out.

while in AC volts

Okay. Will do.

the phone was moving too much to read the screen

I see. I will up my precision by using a stand for future videos.

I think logging into youtube if you have an account will ensure they play. But I understand if you don't feel the need to comply with their BS.

By the way, I just received 3 more OBD readers from aliexpress just this minute. I ordered several types to use on this and future car repairs.

Just got a GODIAG GD101, a Multidiag v3.0 and one Lexia 3 that the french site said was satisfactory, so we'll see if this one works today..

https://www.aliexpress.com/item/100....order_list.order_list_main.65.307b585a49eoUF

https://www.aliexpress.com/item/100...der_detail.order_detail_item.4.51d6f19cNzbYau

https://www.aliexpress.com/item/100....order_list.order_list_main.77.307b585a49eoUF



Still no FULL CHIP Lexia 3 cable yet though.

 

[MickeyS70]

Here are the results of the tests between the UVW leads.

This is an AC motor, need to set your DMM accordingly

I wonder if I can start the car in N and see if it won't error and actually spin the rear wheels?

Don’t think so, has to be in P to start.

Don’t forget to do below and while you’re at it measure resistance between U/V/W:

kiev said:
If the motor has a shorted winding then spinning the wheel may be difficult as if the brake is holding. You can get a feel for this by connecting 2 motor leads together and try to spin the wheel, then connect all 3 leads together and try to spin the wheel. A shorted winding will also have a distorted or lower amplitude sine wave, or no voltage output at all.

 

[Rational]

This is an AC motor, need to set your DMM accordingly

Oh, I wasn't quite realizing this is an AC motor. Thank you for nailing that down in my mind firmly from here on out. Got it. Will do.

I was also forgetting about connecting the motor leads together to see if it increases turn resistance. Will do.

I've got the tire off now and opening up the drum brake now to see if it's rubbing.

 

[MickeyS70]

Okay. Here is the i-miev motor UVW resistance test results video

Measuring coil resistance is a static test, need to set the DMM to it’s highest sensitivity (mOhm)

 

[kiev]

Resistance is a static measurement from phase to phase. No wheel spin for that.

It appears that your meter was reading 000.0 Ohms, which is basically zero. The resistance is likely in the milli-ohm region which your meter may not be able to measure.

What about measuring resistance from motor phase to chassis? Do you get any reading or is it open?

====
The back-emf voltage reading is measured while spinning a wheel. When back driving the motor is acts like a generator, where the voltage is proportional to speed. The faster the spin, the greater the voltage. The main thing trying to do is just to determine if, while spinning the wheel at about the same speed, then the voltage is about the same for all 3 cases. If one of the phases were shorted then the results involving that phase would be lower.

Hopefully you found the brake to be dragging and it can be relieved to spin freely.

 

[Rational]

Okay. I got the drum cover off finally. Had to find two 12mm head bolts to use in the two holes to separate the drum from the car.

I'll post two pics of before and after.

Hopefully you found the brake to be dragging and it can be relieved to spin freely.

Yep. You're right again as always.

I can confirm after removal that all the resistance seen and felt before was entirely from the drum brakes. Right now I am able to spin the axle with a lot less effort by hand.

 

[kiev]

Great progress, i'm gonna have to drop off for now and let Mickey carry on. i'll check back later in the morning...