Landspeed's HV battery + ECU teardown, analysis, experiment, upgrade thread

I would also love to know where to get this connector. Seems that's all that's ever gone wrong with my Priuses battery computer. And I'm wondering if this wiring harness that goes from the connector over to the battery blocks has been discontinued?

 

Vaguely remember someone sourcing such, have you already tried searching the bowels of PC?

Still exists (the feds have laws), please post if you find a better price :
8216547040 - Toyota Wire, frame, no. 2. Battery, electrical | Roseville Toyota, Roseville CA

 

I was wondering that too. Where to look? Since there are those spare seven pins, I'm going to cut and resolder the pins and relocate all the wire connections to the undamaged part of the plug, and sand/file away the charred bit. I wonder if a good spray of WD40 would keep the damp and corrosion dragons at bay... It looks like the white block in the wiring loom plug clicks-out to release the pins (after taking the loom off the battery of course!! ;-) )

 

Actually, given the level of frustration finding the exact keywords for the search, I´m considering just buying and mounting a 15 pin D plug and socket. The voltage rating is 500 volts, and the pin spacing is 2.77 mm. The key will be to make sure it´s vibration and bump proof. Then wire in to the residual pins and sleeve to avoid moisture. We used to use silicon grease in our electronics lab for this. I live is a place with very salty air, so having read some of the other threads about this very common problem, I think this might work okay.

 

So it seems that the green corrosion is hydroscopic - it attracts and holds water, and if the air is salty and damp we have the perfect conditions for this problem to manifest - so it is a design inadequacy (not necessarily a fault). You´d think this problem would also be common in Japan?? So, as the corrosion proceeds the greater the potential for an eventual short and fire. And regular cleaning would be ideal, but otherwise a sealed socket where the pins on the board and the wires from the loom are also sealing with a potting compound would be a good preventative measure...

 

Thanks for that link. $56 is a nice price except they won't ship to Hawaii because the dealership here has some type of exclusive rights to jack up our prices so locally it's about $300. I'll probably find it on eBay.

 

You've done so much work already! The CPU core and instruction set should still be similar/the same, even with all the different accessory packages. Once you get a bin it will be a lot easier to understand what is going on.

It looks like k-tag has support for the ECU. You may be able to contact them and see about getting something for the HVMCU (I think Motor Control Unit is more appropriate).

You don't need a frame, just small wires and solder. K-Tag clone boxes are pretty cheap.

I can't post links yet, sorry.

youtube Txmm3zizbwk to see a successful read of a 175822-773 with micro 76F0038GD out of a Rav4

Check out 152-k-suite-update-v2-19, they list all the 76F00XX in Prius ECU, not sure about HVMCU. K Suite is on version 4.17 now haha

My main interest is in the ECU, I would like to use the 1NZ for a project either without a hybrid system or with a stand alone brushless controller. You really don't see many people tuning NEC/Renesas units from Toyota, it's so strange.

With the NEC JTAG setup can you monitor the RAM data as can be done with BDM and STLink SWD tools for Motorola and STM? Poking around in the brains of a running ucontroller going through the mystery code can really help development.

The lock bit is usually a burnt fuse. It's possible they made part of it locked with that fuse, but doubtful. Especially with the throttle debacle it would have been terrible to replace all the physical ECU boxes rather than update the code.

 

I had the connector corrosion problem with a 2012 Prius C. The pin adjacent to pin 22 was green and corroded all the way through, right where the pin goes into the PCB. I replaced the sensor module with a new one from a Toyota dealer and now, 6 months later, the new one has failed in exactly the same fashion. Same pin and everything. Oddly enough, shortly before the first failure, the 12V battery failed and I replaced it with one from the local Toyota dealer. I wonder if the vent is not doing its job, and fumes are getting into the sensor module??? On a Prius C, the 12V battery is just a few inches away from the sensor end of the HV pack, underneath the back seat. It is humid here.

I am considering one of two fixes. Either move the pin to an unused one at the end, or run a separate (well insulated) wire into the case. Moving the pin would be my first choice but I am having trouble removing the female pin from the connector. Does anyone know a trick for that?

 

> Does anyone know a trick for [removing connector pins]?
Never mind; I figured it out. The key search term is "de-pin". And then there was the problem of corrosion on the pin that jammed it in the plastic, despite disengaging both locking tabs...

 

So, when you replaced the ecu before, did you also replace the harness (connector) as well?

Posted via the PriusChat mobile app.

 

Did you see the comment above?

 

It may not be enough to just replace the pins. Problem pins usually mean problem wires.

 

No, I did not. Prius C harnesses are not easy to find. I have since figured out that it should be possible to build one from a regular Prius harness and the old Prius C plastic.

Can you elaborate on the mechanism whereby the wires would affect the pins?

 

I would be very interested to know the mechanism whereby the wires damage the pins. How does that work from an electrical or electrochemical standpoint? I am well acquainted with electronics in general, but quite ignorant of the special considerations of the automotive electronics environment.

 

Serendipitously, this was mentioned very recently in another thread:

 

The voltage sense wires that go to the battery ecu have very high electrical potential. Add in high ambient humidity, and you have a recipe for corrosion. Don't know the scientific details, just know that it happens.

Problem is, that causes damage to both the male AND female terminals in the connector. So you need to replace both at the same time, otherwise the connection will fail again as the old corroded terminal in the connector will cause more corrosion.

Posted via the PriusChat mobile app.

 

Thanks. After a bunch of searching, I found an ebay seller with a Prius C sense module and harness, both corrosion free, and ordered them. Hopefully this will be the last time I have to take out the back seat and frame, yada yada.

 

Well then we concur, crap battery designP

I think another issue is the pressure relief valves get stuck as noted by the fellas doing the rehydration attack.
So if this is the norm, then the batteries are forcing the next level pressure relief through the negative posts. Giving us the electrolyte leaks, bus, sense wire and ECU connector corrosion....cheers

 

One thing that can help prevent the connector corroding so quickly again is to always use the HVAC, and always use it with the compressor not turned off. Even when not actually cooling the cabin, this dehumidifies the air and keeps the interior and battery drier.