2010 Prius Stuck in parking, P3004 P0A0D error codes

I bought an used 2010 Prius which has always been serviced Toyota dealership and it had an extended third-party warranty. Few months after I have been using it, one day it was stuck in parking with all the usual warning lights indicating a bad hybrid battery pack along with the dreaded "Check hybrid system" error. I already had another 2010 Prius prior to this which I had see this error but without the problem of not able to shift gears. So I reset the safety service plug and its on-board computer and still cannot clear all the errors, and the car was stuck in parking.

I ended up towing it to the nearest Toyota dealership, I suspected based on the troubleshooting I had done, even if the battery pack was going bad it should still allow me to at least drive the car with lower fuel economy, so it is probably the inverter. They diagnosed with a short in the battery pack which did not allow any current going to the inverter. Before they can troubleshoot the inverter they would need a new battery pack. I balked at it as it cost a lot of money, but in the end I got another one from a company which regenerate high quality Toyota original cells with a good warranty. The warranty policy covers about half of the cost at this point.

After the battery pack arrived, P3004 seems to have disappeared but P0A0D error still remained. Toyota technician now confirmed that it was the inverter. A new one cost nearly like a new battery pack, so I ended up finding a used one from a newer model (2012-2018 Auris) that has a different part number (G9200-47190) which is also compatible and better. This solved the problem and the car works.

I ended up making a video about this to help others who have this particular problem:

 

I actually thought that it would cover the entire cost, but reading the fine print and after the customer service's clarification I understood that they only cover partial cost of replacing the part to restore the car to the condition to which it was sold. Since it was not a new car, the reasoning is that they cannot cover the cost of a new part. Initially for the battery pack they were going to give just 500 euros, but after some negotiation I got that bumped to 700 euros. Then for the inverter, they initially wanted to give 750, but I got it bumped to 1000 euros. This was based on the price I was quoted by Toyota for a new inverter. They just need the official diagnostic report and quote and will provide an amount which they can pay. Then few days later the money arrives in my bank account, and I can use it buy from any source. The dealership was really good, they kept the car for more than a month while I was finding and waiting for the parts and only charged me three hours of labor totally about 250 euros after tax. So I paid out of pocket about 500 euros overall.

 

In fact, I really did not want to replace the battery pack unless it was absolutely necessary. The battery pack, even if it was becoming poor and in need of replacement can still be used for some time as long as there are no other issues. I tried to do the reset by unplugging the service plug and it did not do the job. In the end, if it were not for the warranty program covering majority of the cost and the fact I could find regenerated and used parts, it would have been an unacceptably high price to pay for the replacement of parts using Toyota parts. If they had a spare battery pack to use for troubleshooting (which they didn't) they could have found that the inverter needed more replacement than the battery pack.

 

The technicians removed the battery pack and traced the circuit to the inverter, and even removed the inverter too. I was there several times to see this myself. There was unfortunately a short within the battery pack which didn't allow the power to arrive at the inverter, which is why it had to be replaced first.

 

I really appreciate this detailed information as I had no idea about this. If I had access to the diagram it is likely I can insist on where to check (at the risk of telling them how to do their work, it's worth it). I too, thought it could be a less expensive repair. Though lesson learned, next time I will be armed with this info and insist on it.

 

I got an used one for less than 500 dollars. I have seen them from 200-600 on various classified web sites.