P0AFA - Battery Sensor Wires ALL COMPLETELY burned - Sherlock Holms needed!

First, I would sincerely thank this forum for providing valuable information to all Toyota Hybrid owners! Because of all the isosteric info I was able to find here, I've been able to troubleshoot my hybrid issues within minutes and save countless thousands of dollars!

Second, I'm calling on all here experts to check out my case and suggest what happened to my car (I think, it was sabotaged - any idea how exactly?).

Background: 2007 Camry Hybrid (essentially the same Hybrid system as Prius Gen 2) the car is being exported from US (US model) to Costa Rica. No codes, no issues at the start. The car has been sitting without running for 7 months in a very humid conditions. The importer/dealer has an incentive to sabotage the car - to charge me for replacement HV battery ($6k here). I took the car away from them to investigated it myself.

First check brought up several codes all of which were cleared, but one: P0AFA (Hybrid Battery System Voltage Low). I've started to take battery apart and noticed signs of fire. When I dug out the Battery Sensor Module, the sensing wires (orange) that go into it where half melted and where sparking - See pictures. Yes, I know, it's RIDICULOUSLY DANGEROUS. The orange plug was completely melted into the module. It's not the usual 1 or 2 pins that get a bit scorched - the whole thing melted (as if, somebody applied a ridiculous voltage to it)

The battery, measured directly, is outputting a relatively healthy 190V
The sensing wires have been all disconnected to prevent another fire.
I'll fix it by replacing the wires and the module - that's no problem.

However, the main question is: HOW DID IT HAPPEN?
Could it just happen by itself, while sitting idle?
Could it be some kind of sabotage? (Like shocking some part of battery with a large capacitor or something like this?)

 

Hi Tom,
I can't take pictures right now - too dark - will try to take them tomorrow.
But to answer your question the "fire" is localized around the orange plug of "Sensor, Battery Voltage (89892-33010)"
I didn't see anything unusual in/around the actual battery.

As far as I understand, this orange plug is a typical point of failure.
I see many posts that show the burned pins inside of the plug.
But none of those are on the scale that I have here.
Basically, all 20 (or so) wires melted together, short-circuited with each other and exploded.
I see tiny pellets/balls of melted metal on the bottom.
Even when I was trying to take it apart it was still sparking (scary nice person experience BTW!)

Also, I have one more clue to add to this puzzle:
The "ground wire" (small 20cm black wire that goes from the battery enclosure body to the HV "-" on the control module) was loosely connected. In other words, the HV battery may not have had a good ground. Would that influence anything?

"Anything going on up near inverter?" - Yes!
The inverter in this model in under the hood and it has a plastic cover. The first time I've opened the hood that inverter cover was on the other side of the engine bay - just laying loose on the engine block! Good luck that car didn't start; otherwise, that could've been chewed into the engine. Yes, I am dealing with complete retards for mechanics over here. The actual inverter seems to be ok - all bolts are tight, HV wires in good condition.

Additional Background: before dealing with current issue (P0AFA), I have actually tracked down and fixed the P0A0D - it turned out that the BIG orange disconnect safety plug did not completely insert into the "small" plug (when it is pushed down) to indicate to the computer that it's plugged in.

What I'm trying to say, is that I'm 100% somebody did something!

 

Yeah, after sleeping on it for a night, I'm starting to think it could have happened by itself too...
Especially, because this specific car has a bunch of circumstances that could've made it worse:
1. Continuous high temperature: 30*C+ for months without ventilation or start
2. High humidify (Costa Rica)
3. Continuous "shacking" (boat shipping, then for months it was towed from various warehouses to others)
4. People who completely ignored all of the initial warnings

I think, it could've have started with just 1 or 2 wires melting like in the regular case,
but because of the "special circumstances" above it got worse and worse overtime.
It also might've been "self reinforcing" chain reaction - the more wires melted the more it effected wires next to it and then they melted and affected other wires next to them..

I will definitely check out the Thread about battery ECU fires...
Thank you!

 

Hi TMR,
Thank you for correcting me. Coming to think of it: the 190V is not good... Later on I'll check it more precisely and will inspect and measure each module. About 3 years ago, I've replaced one of the modules on this specific battery, so it's not all "original." I have 2 replacement modules standing by.

As for sabotaging... yes, I think you right: nobody did it. It was just a bunch of unfortunate circumstances that came together.

 

Hi Douglas,
I see how it may seem that during transport and import process the broker and importer would be responsible to "maintain" the car. And it is kind of correct when it comes body and drivetrain - they are responsible for "maintaining the state" of those (aka not to damage body and/or tear of any body parts, components during shipping). But when it comes to electronics, computers, HV batteries, or some other internal components - no. If those break, it's my problem. They can fix it ($6k for HV!), but they are not responsible.

Also, please remember it's an old Camry - there isn't much value in it. The whole idea was bring a beater car here. So starting some kind of argument with these people over a few $k is not worth it. Also, I'll need to take it back to them to finish "naciolization" - because right now the car is illegal.

IMO, it's just easier to replace the $100 component and move on; then to argue with them months on end about who is responsible. Things work differently in Latin America...