P0A2B Red Triangle of death after transaxle replacement

Hi Everyone,

I recently purchased a 2006 Prius, the owner said the car shut off while on the highway. He had it towed to the dealer and they ran diagnostics and they stated that the electric motors were bad in the trans-axle and it need to be replaced. It was getting codes P0A2B,P0AA6,P0A78

I bought the vehicle from him and purchased a used trans-axle. I replaced it myself and got it all back together, started it up and was having the same issues. I had the vehicle towed to the dealer where they wanted to just start throwing parts at it. They said they weren't sure if it would fix it but they wanted me to replace all 3 computers for around 4k. They were getting codes P0A08,P3102, P0852

I had the vehicle towed to a different shop for another opinion. They told me that the only code they were getting is P0A2B. Which they said was the temp sensor for the motors in the trans-axle that was not replaceable. I contacted the company i got the trans-axle from to get a replacement. I put that in on Saturday and i am now having the same issue. Same code.

I spoke with a Toyota tech who was very helpful. He sent me some wiring diagrams and told me which wires were for that sensor. I cut them at the trans plug and at the computer plug and ran new wires. Still the same issue.
My scanner reads the temp for MG1 at 68 degress and MG2 at 401 degrees all the time no matter how long the car runs. Obviously it is putting the car into some type of limp mode.

The first time the car went to the dealer they replaced the HV ECU. I am now thinking that the Engine computer where the sensor wiring goes into is bad. Does this sound realistic? I ordered a replacement off of ebay, just waiting for it to come in.

I wanted to get some other opinions on what i can do to figure this issue out. Also does anyone know how to replace that ecu? I looked on Identifix and they call for 1.4 hours of labor to R&R but it didn't look like it would be that long.

I am very knowledgeable with cars, just not with electrical.
Any input is greatly appreciated.

 

Thank you very much. I did order a new HV ecu and the main ecu. I will replace and see what we get. I should have them by the end of the week.

 

It worked. Thanks for confirming what i had narrowed it down too. Replaced the HV ECU and did the relearn and she is ready to roll