P0AA7-00 battery pack voltage isolation

Update, this error is coming also from faulty bpcm, we installed another one and it's working. So now we need to compare both to see what's damaged

Great that you got it working!

So this whole time it was a bad BPCM? (causing pack voltage & contactor faults, and intermittent DC-DC & PIM faults)

I suppose you're trying to do it yourself instead of using the place you posted about that repairs them:


That you posted on this thread: 500e Positive Contacter fault, won't drive

That's correct. I found local guy that is very smart and we work together, that's good lesson.
He fixed electronically my BPCM and trying to find what causes in it to make this error. Once all done, i'll write all about this
Currently looking for BPCM pinout

Finally after fight with bpcm till 3am we found another electronic element was bad. Fixed and now car is completly errors free

@caniggia just to confirm - the BPCM you had to repair was in the battery pack?

Correct

@fiatatat might want to compare symptoms & error codes to the @canniggia car

If I recall correctly:

• The @canniggia car just suddenly died completely & ALL of the usual tricks failed.
• The @fiatatat car was temporarily resurrected twice with a few of the usual tricks post #23 here:

Symptoms and codes are identical, and they consistenly return after resets. I'm now working with the guy from Poland to check if we can diagnose or do something about this remotely, and will go from there.

Good news is that the pack cells seem to be okay. The positive contactor is stuck on open though.

I think you are working with guy where my car stucked for 4 months and was not fixed. Charged money agd stopped pick the phone for 2 months. I was lucky i was able to take my car and other guy fixed my bpcm in 2 weeks. I bet you have same issue as mine

@caniggia just sent you a PM.

fiatatat said:

Symptoms and codes are identical, and they consistenly return after resets.

Click to expand...

Please confirm that you tried every trick, in sequence, from the recently-updated post #1 here:

HOW TO FIX A "DEAD" 500E that suddenly...

Hi, I am having the same errors as you noted in your posts (postive contactor error, only neutral & park, etc).
May I ask where you got your car repaired? I tried to PM you but I just signed up so can only make posts.

caniggia said:

I think you are working with guy where my car stucked for 4 months and was not fixed. Charged money agd stopped pick the phone for 2 months. I was lucky i was able to take my car and other guy fixed my bpcm in 2 weeks. I bet you have same issue as mine

Click to expand...

@johnnieosaka check out this thread: Repair Options if Easy DIY Fails. 5/18/23 Update: Fresno...

That's great advice, & @johnnieosaka might also want to check out this thread: HOW TO FIX A "DEAD" 500E that suddenly... to make sure it's not just false-alarms preventing operation, which is much more common.

Thank you so much for your help, this thread is awesome!
I tried everything that I can at home so far regarding trying to "reset" the system (HV fuse, new 12v battery, humidity sensor, clearing OBD codes etc).

Brought it to a nearby dealer paid $200 and got a similar printout regarding positive contactors which @caniggia posted and was told I need to replace the entire HV.

I have a feeling it may be the BPCM and am thinking of sending it here:

I think it will cost roughly $800 to do this, would it be worth a shot or should I just sell for parts? I live in NorCal

If you can post the BPCM log, we can confirm if this is the BPCM failure.
And if it is the BPCM, of course it makes sense to repair. You won't be able to buy an EV for $800.

Agreed. Or at least relay AlfaOBD's onscreen descriptions of any codes that won't stay clear. HOWEVER...:

johnnieosaka said:

I tried everything that I can at home

Click to expand...

It has only been about 20 hours since your first post. Did you really already go 30+ hours with both the 12V & HV disconnected? (after leaving the sensor unplugged)

johnnieosaka said:

clearing OBD codes

Click to expand...

Please confirm that you're using AlfaOBD, & that you turned the key from "off" to only one click before connecting OBD, & left it there, so it didn't think the "engine" was "running".

Sometimes a 500e will get false alarm error codes that prevent operation & won't clear until after 30+ hours without power.

I know that seems extremely strange, but here's what one user reported:

He tried disconnecting for 30 seconds & when that didn't work he tried 5 minutes, which also didn't work. Personally I would have given up, but with nothing to lose, he tried a few hours, which also didn't work, so he decided he may as well try overnight. It was about 30 hours by the time he reconnected, at which time the car then worked fine. I can't remember if he also had to clear some remaining codes, but other users have had to.

Since then, other owners have had success with code clearing after 30+ hours, when 5 minutes hadn't worked.