Long story : P0AC0, P3000, P3004

Hello from a french Priusman !

I bought a used 2008 Prius 2 in july with 82,000km/51,000 miles and drove it 1000km/600miles before having problems.

August 2020 : with OBD2 and Torque I searched for errors and it gave me P0AFA and P0AC0.
So I took the battery apart and cleaned up the corrosion. Check the condition of all sensors and the ECU box. Each cell of the battery has been tested with a multimeter (voltage and resistance), then under voltage with a headlight bulb. She is fine.
I put everything together and the car ran perfectly for 400km/230 miles.

September 2020 : new error codes P0A90, P3000 et P3004. Helpless, I go to Toyota dealership and ask for a diagnostic : dead inverter. Ouch ! Repair costs : 3420€/4000$.
Desperate I accept and tell myself that this will definitely solve the problem.

October 2020 : After 6 weeks without a car, Toyota returns my Prius with a new inverter and it droves fine. Two days later I go shopping and when I start the car the error lights come on! OBD2 and Torque shows errors P0AC0, P3000 and P3004.

Now I don't know what to do. This car is a disaster.
The voltage of the 12v battery at rest is 12.45v. Torque and Dr Prius shows me all good battery elements.
Maybe the HV ECU box is the culprit? What do you think ?

Thanks for your help

 

The Prius has just returned yesterday for a diagnostic at Toyota Dealership. This time the technician accuses the ECU box which is next to the hybrid battery. He would also have noticed humidity in the trunk so will proceed to further check the harnesses and connectors this Friday.
To be continued...

 

Thank a lot @PriusCamper!

Corrosion in ECU and harness plugs
I cleaned it in August and the car ran well for about 400 miles before showing again P0AC0, P0AFA. But I really have the feeling too that there is a problem with that because the car spent all his life not far from the ocean (salt and humidity in the air). So maybe the wire frame n°2 is faulty.

Toyota dealership
I told them that I don't understand how they can give me the car back with new errors despite a recent expensive intervention on the inverter. On the bill it's written "Test of the car on the road after repair" and they surely did not! Otherwise they would have detected the P0AC0. Car is currently being tested again and mechanic is searching for problems with harness and connectors. I see that they feel a bit guilty in their attitude even if they will never say it.

In short, I'm waiting for their final verdict but I won't buy anything from them anymore! I'm also opening a litigation thanks to the
legal protection included in my insurance contract. Wish I can get my money back...

 

Okay final answer from Toyota Stealership : ECU is failing (the one next to the NiMH battery pack).

They refused to admit that there was a misdiagnosis on their part. No refund. No guilt. No support.
Worse, they ask me 900 €/1070$ more to change the ECU. Of course I declined.

I am absolutely frustrated and pissed off. Never had such experience of incompetence and bad faith.

It's time for legal proceedings now! ...

 

@fotomoto no trace of water found. I did inspect it too.

@PriusCamper I give a try. It will take weeks but I still have a chance to be partially refund or receive money to repare the ECU with a brand new OEM.

Finding a used battery ECU for Prius 2 in France is rare and expensive. Toyota sold so many more Prius 1, 2 and 3 in US!

In general Asian car brands are not the most frequent cars you can see here. However Peugeot, Renault, Citroën, Volkswagen are everywhere.

 

@PriusCamper I'm ok if you can sell me the ECU and I will pay the expedition.
My original ECU has the reference 89890-47092.

@SFO I had a look. My god the prices are crazy and no ECU found. Swedish currency is expensive/high.

 

I ordered a brand new Toyota Wireframe n°2 on Ebay. Now i'm looking for a used battery ECU.
Onece I receive both and install it everything should go better. Really hope !

At the same time the legal procedure to find an amicable solution with the dealership is initiated. If no answers, it will go further.

 

II bought a used battery ECU today. But working.
Still waiting the Wire Frame n°2 ordered in japan.
I'll post some news at the end of november to tell you if everything is right again !

 

@PriusCamper you're so right

For information, here are pictures of my ECU and the Wire Frame of the battery pack before I cleaned them in August. I think changing them is the best option because it had a lot of corrosion.

 

Hi
Some news today I changed the WireFrame A and the battery ECU.
I did a test run of the Prius and it droves fine for 15 miles. No error code, no lights at the dashboard.

Then suddenly red trangle came up again with the red logo of the car on the display screen. My HV battery suddenly dropped from 6 bars to 3 bars and engine stayed alaways on.
I went back home and tested with Torque Pro.

Errors are P0A90 and P0AC0.
Exactly the same I had the first time. And since then my inverter has been replaced by Toyota and I changed battery ECU and WireFrame 2.

I'm quite lost :/

 

Yes when error showed up I lost acceleration. No more power under right foot. I had to restart the car to have power.
I'm wondering if the problem since the beginning isn't something with the transaxle.

To be sure I also re-checked the coolant of the inverter and my 12v battery -> all fine.

I'll check the inside of the battery ECU tommorow. And check the connections of the hybrid ECU in the dashboard too.

Although i'm wondering why the problem shows after 15 miles and not since the start of the car. Looks like something heat and the make an error... or something like that.

EDIT : Next week I'll buy a new 12v battery just to be absolutely sure that the problem doesn't come from here. I found a brand new Varta A15 for 48€.