2007 Prius with Red Triangle and DTC P0A63.

I am not a mechanic and I have a 2007 Prius with sporadic P0A63 error. No others. Took it to Toyota and they reproduced the error but then could not. After they kept the car for a week, they still could not tell me the issue and I took the car back. The service agent said the repair might be $5k. After clearing the code, the car works fine (sometimes) but is not reliable. I have cleared and limped the car home several times. Sometimes I go for a week without the error reoccurring. HV battery shows 68% life left and 217v with no bad cells, 12v battery shows 14v when running and 12.7v when stopped. As far as i know P0A63 error is for inverter, inverter pump, or controller. What do you think the issue is? Do I need to replace the car? Why can't the dealer find the error? Thank you for whatever advice you can give.

 

Sorry about the graphics size.

 

I have a 2007 Prius with 140k miles on it. Recently, I have been getting the red triangle of death and engine lights on and off for the last couple of months. I have had it to my mechanic and Toyota 2 times. The last time they kept it for a week and could not find the problem. It appears sporadic and the only error code is P0A63. When this happens, the car goes into limp mode and I pull over, erase error code, wait 5 minutes, restart, and then the car runs normally. I have only been doing this because Toyota could not find the error. It appears this must be a sensor issue and not actual inverter or inverter pump otherwise why would clearing the code stop the error. HV pack voltage is 212-232v and blade voltage is 8.32v. 12v runs 12.1 to 14.1 (when running). Full battery test runs normal with no errors. All cells seem OK and battery pack has 66.82% capacity left (fair). No engine ECU errors found. After P0A63 error code is cleared no HV battery ECU error codes are found. Any ideas? The only suggestion from Toyota was that the repairs might be $5k but they could not tell me what they would do after keeping the car for 1 week. Thank you.

 

Hello Sam, OK I took it to a hybrid specialist but the shop had more regular cars than hybrids and it would take a full week to look at in a dangerous area so I went back to Toyota for the 3rd time. Here is what they are saying...
THE OPTION FOR YOUR VEHICLE; TRANSISTOR AND ECU IS $5,667.70, HYBRID ASSEMBLY AND ECU IS $6,032.99.
I know that is over the worth of the vehicle but...