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

[Mia272]

Hey, welcome to the forum!

About the motor – at 200,000 km, it's doubtful the motor itself is the issue. I’d lean more towards wiring or the MCU, like you mentioned. OBD should give you a clear direction, so definitely check the error codes. Great that you already have experience with the Leaf – that'll help for sure!

Also, if the 12V battery was replaced, the issue might be with the relays or BMS. Worth checking that too! 🥸

 

[Rational]

I received the 3rd MCU today.

I decided to open it up immediately upon arrival to check the IGBTs before we connect this MCU. That way we have a baseline to know the condition should they get damaged later, we'll know they were good before they went in the car.

I recorded a video of me testing the resistance of this 3rd MCU in comparison to the 1st original MCU that was in the car with the damaged IGBT.

I couldn't test the 2nd MCU yet as it's still in the car. No time tonight for that one in comparison.



I also have to move the MCU power leads as the guy kindly cut off the connector for me before shipment. Thank you guy. Props.

 

[Rational]

Okay. I've been able to move the orange power leads over from my original MCU to the 3rd MCU now.

He also cut another wire I finally noticed, so I had to move that as well. All done.

I also tested the MEIDEN capacitor. Seems it is 40.00 M-Ohms on average from each pair of leads.

 

[kiev]

The visual appearance of the die pads under the clear gel looks good for the newest MCU (#3), especially when compared to the burnt pads and bondwires in MCU #1.

Just fyi,
The "M" is for MegaOhms, 1,000,000's
"k" is for kilo, 1,000's
and "m" is for mili, 0.001's

Checking a capacitor using resistance measurement is only useful to show if it is shorted or open. The meter leads will charge up the capacitor so the reading will fluctuate and the number has no real meaning, except if it reads 0 Ohms it is shorted and failed.

Same goes for the IGBTs, resistance has no real meaning except it can indicate if a junction is shorted .

The diode check function is used to measure the diode drop voltage of the PN junctions of the transistor, and of the free-wheeling diode.

 

[MickeyS70]

The diode check function is used to measure the diode drop voltage of the PN junctions of the transistor, and of the free-wheeling diode.

What @kiev refers to is best illustrated in the schematic on page #145, each of the 3 IGBT modules seems to contain an upper and lower gate each with a freewheeling diode across.

For more details on how to test an IGBT with a DMM check out video below

 

[Rational]

What @kiev refers to is best illustrated in the schematic on page #145, each of the 3 IGBT modules seems to contain an upper and lower gate each with a freewheeling diode across.

For more details on how to test an IGBT with a DMM check out video below

Great video!

So seems like I should retest the three new IGBTs in MCU #3 with this proper methodology to 100% ensure they are good.

 

[Rational]

Just fyi,
The "M" is for MegaOhms, 1,000,000's
"k" is for kilo, 1,000's
and "m" is for mili, 0.001's

Thank you for this. I'm finally learning to use a DMM correctly. It's about time. Feels good.

Checking a capacitor using resistance measurement is only useful to show if it is shorted or open. The meter leads will charge up the capacitor so the reading will fluctuate and the number has no real meaning, except if it reads 0 Ohms it is shorted and failed.

Same goes for the IGBTs, resistance has no real meaning except it can indicate if a junction is shorted .

The diode check function is used to measure the diode drop voltage of the PN junctions of the transistor, and of the free-wheeling diode.

Okay. Thanks for this and the video Mickey shared. Making perfect sense now. Seems I should retest properly again with correct knowledge.

I will also post this video link under my improper videos so others are aware of how to do it correctly.

I'll also create a new video showing how to check the i-miev IGBTs properly for others in the future.

 

[Rational]

I also will work on getting several old laptops set up today for the three new scan tools I just received.

I'm going to set up one for Win7 32bit. One for W7 64bit and a third for W10 64bit. I'm also setting a restore point so I can reinstall from a fresh baseline as the software is flaky from these Chinese CDs. So a fresh reinstall of the apps is usually best to ensure things if I have to start over.

I want to try and read my original MCU #1 chassis number and any other important info like the motor phase angle while it's still connected.

I just need to figure out which software and where within it to gather this info.

 

[MickeyS70]

I just need to figure out which software and where within it to gather this info.

The Lexia cable is designed to work with Diagbox, don’t use the CDs delivered, they contain malware. Try the images posted on the PSA website (your post #60), there is also tons of YouTube videos.

Diagbox seems to work slightly different to MUT3 as a lot of functions are combined and found in the repair section under the individual ECUs

 

[Rational]

The Lexia cable is designed to work with Diagbox, don’t use the CDs delivered, they contain malware. Try the images posted on the PSA website (your post #60), there is also tons of YouTube videos.

Diagbox seems to work slightly different to MUT3 as a lot of functions are combined and found in the repair section under the individual ECUs

Okay. Will do. Thanks for the advice.

I am using old laptops and keeping them offline and dedicated just for this as I'd heard about the malware thing. It's true. My main PC is detecting them in the installers and downloads from the websites. Fun.

I'll try Diagbox with the full chip cable when it arrives. Sadly the current adapters I received do not detect as PSA VCIs.
So I'll have to wait for that one.

But do you know which VCI will work with MUT3? Just the original MUT3 device, Tactrix openport 2.0 real one and scanmatik 2 pro?

I'm a little worried that the european diagbox may not like that I don't have a full VIN number and only a shorter chassis number.

Wondering if I need to use a Japanese version of MUT3 and adapter only perhaps?

 

[MickeyS70]

Okay. Will do. Thanks for the advice.

I'll try Diagbox with the full chip cable when it arrives. Sadly the current adapters I received do not detect as PSA VCIs.
So I'll have to wait for that one.

Try the current lexia cable when you have Diagbox up and running

But do you know which VCI will work with MUT3? Just the original MUT3 device, Tactrix openport 2.0 real one and scanmatik 2 pro?

Sorry, don’t have any experience with MUT3, someone else might jump in here..

I'm a little worried that the european diagbox may not like that I don't have a full VIN number and only a shorter chassis number.

Shouldn’t be a problem with auto detect, hopefully diagbox is only looking for 17 digit VIN when entered manually

 

[Rational]

Same goes for the IGBTs, resistance has no real meaning except it can indicate if a junction is shorted .

The diode check function is used to measure the diode drop voltage of the PN junctions of the transistor, and of the free-wheeling diode.

Alright. I've properly tested the IGBTs in MCU#1. Now that I understand better what I'm doing. Thank you.

I've confirmed that Gate 2 in the middle IGBT (which I think is IGBT#1) has shorted out. As it shorts to Gate 2 pin 2 as well as Emitter 1 pins as well as the high power Emitter 1/Collector2 shared bus bar.



I will now take apart MCU#3 (again) and properly test the IGBTs before mounting it in the car for further testing.

 

[Rational]

I've now tested MCU#3's IGBTs completely. They are good.



I am now opening up MCU#2 to test the IGBTs but it's 10pm now here so not sure I'll get it done tonight.

 

[Rational]

Well, MCU#2's IGBTs test out good.

I'm getting fast at testing them as well. It feels good to know how to know for sure something is good or not.

I also removed the left rear tire and drum cover. It spins freely now. Motor is smooth.

So this seems to me to indicate the cause may be in another area.

1. The brakes were too tight. Doubtful but a possibility. I don't think they were seized enough to cause an error as I could spin them by hand.
2. The MCU controller board was damaged and causing the P1A2A error to persist.
3. A problem with a wiring harness I've yet to search for and find.

But based on the current condition I plan to:
1. Put MCU#2 back together with the original controller board from MCU#1 from the car when it had the P1A2A errors.
2. Connect battery and main fuse, leave motor disconnected for first test.
3. Retrieve codes and see if they are still gone. Start in Neutral for this test and see if it will start in N.
4. If that passes, start in P and switch to R and see if engine check light appears and errors are thrown or not.
5. If not, reconnect motor and see if errors reappear or stay gone. Especially starting from P and moving it to R.
6 If errors are gone I'm done.
7. If errors reappear I will have to suspect the controller board or wiring loom somewhere.
8. I will also try to gather info via Diagbox if possible while I still have MCU#1's controller board connected to save the original data.

Next step will be to:
1. Swap in MCU#3 to compare if any codes are thrown for P1A2A or not.
2. Probably not since I've confirmed the IGBTs are good. And assuming the control board (#3) is good. (Unknown).
3. Check for VIN/Chassis mismatch errors being thrown which would be correct.
4. See if car moves (wheels turn while jacked up with tires off and drum covers removed.) Unlikely. But worth testing.

Decide what to do from there.

 

[kiev]

We are curious-- so fill us in about trying to start to READY without the motor windings attached?

Is this a troubleshooting and diagnostic step for motor drive inverters?

Could the inverter do any sort of self check that energizes the windings, and would fail? Would it be a graceful failure, or maybe not and take out some IGBTs ?

 

[Rational]

We are curious-- so fill us in about trying to start to READY without the motor windings attached?

Is this a troubleshooting and diagnostic step for motor drive inverters?

Could the inverter do any sort of self check that energizes the windings, and would fail? Would it be a graceful failure, or maybe not and take out some IGBTs ?

I'm just taking the advice given earlier to see if the DTC codes don't appear while having the motor disconnected should that still be the cause.

Am I misremembering that this advice was given to me? Would it not at least give me more information to go off of while I still have the motor disconnected?

It seemed to help when I first tried it as it allowed me to get into D and R from N with it detached and the P1A2A was no longer appearing with the motor disconnected. Is that not further information and progress than we had before?

I figured since I still had the motor wires disconnected it might be good to see if the DTCs still aren't appearing one final time before I reconnect them. And to further retest if they appear when starting from P and shifting to R with it still disconnected. Thinking that would confirm that the error is not with the motor but within the MCU solely. Specifically within the controller board now that I've confirmed the IGBTs are passing DMM tests.

 

[Rational]

Could the inverter do any sort of self check that energizes the windings, and would fail? Would it be a graceful failure, or maybe not and take out some IGBTs ?

I was mulling this over on the way home tonight just now and I really don't know. That's a good question. Two good questions.

So are you saying because we don't know we shouldn't risk it? If so, I guess that's a good point.

I guess I'll hook up the RWB motor leads as it's intended to be installed and test from there. Thanks.

Starting now.

 

[Rational]

Got MCU #2 all put back together and have connected the RWB motor leads as advised. Going to rest now.

By the way, I have been sharing my i-miev journey over on Dala's EV discord channel and it just so happens a guy there asked if he should buy a used ion and try to get it working.

I shared with him this forum and thread here. So it seems he is going to buy it!

Says it does the same thing mine does when you try to shift it into D. Fun times ahead with another member here shortly.

 

[Rational]

Didn't work. Same error. P1A2A. Same as before.

Occurs instantly when I go from P to R.

 

[Rational]

So what’s an immobilizer?

Got autocom to read the vehicle. Shows these same errors.