2013 Prius c has Error when Accelerating and Dies

Hi there! I have a 2013 Toyota Prius c with 91,000 miles. Bought it used in 2017 with a clean title. It has been accident free under my ownership and I perform regular DIY maintenance.



So I was accelerating from a right turn when suddenly, a noticeable thump was felt with accompanying noise from the engine bay. At the same time, the dash lights and buzzer came on with the dreaded “Check Hybrid System Stop Vehicle In A Safe Place Immediately” message. I parked and attempted a restart, but the same errors persisted. I pop the hood, no noticeable smells nor any leaks were found. I got my car towed home and performed a limited diagnosis to the best of my non-mechanic ability. The following are the results:

• I set the vehicle to ON and there is the usual electric initializing noise. I then attempted to put the hybrid system to READY but the same error message pops up. I waited for the engine to start but it did not.

• I checked the fuses related to the hybrid system but did not find any of them blown.

• I checked for any high voltage battery cooling fan blockages/dust build up but did not find any.

• I checked the gas cap and it was snugly fitted on.

• I checked the 12V accessory battery with a multi-meter and it reads fine (the accessory battery was replaced in 2020). I currently have this disconnected overnight in hopes of a memory reset. I will update when it is reconnected.

I do not have any readers to help with the diagnosis (I should probably invest in one). Any tips for further diagnosis would be appreciated. If nothing else, I plan to have it towed to a dealership service department for diagnosis. Once I know what's wrong, I will update.

 

Update: I reconnected the 12V battery this morning but the same error message appears. I will have bite the bullet and get it towed to a dealership service department for diagnosis. On a side note, are there any affordable code readers? Please let me know as I think I might invest in one (thread links appreciated).

Thanks for the info. I got a reading of 12.2 volts. Please let me know where the other end of the battery cable is located and I will check the voltage there as well. I may have to agree, it does sound like the HV battery or inverter may have gone bad.

 

Update 2: I got the diagnosis from the dealership. They say the inverter shorted with code P0A94. The unit needs to be replaced with the following estimate:

Part: Inverter Assembly, with Converter (G920059065) at $2,770
Labor: $350
Warranty: 1 year, unlimited miles

All in, it is $3,120. The service advisor said this is only the third time in his career that a Prius c came in with an inverter short. He also notes that he sees other Prius models also get this issue and are able to refurbish the part, "but not for the Prius c."

I did look around my area for comparison pricing on the part, but most hover around that price range. I did notice that that part number was "incompatible" with my VIN and another part number gets pulled up instead (G92A052020), but that one is unavailable. Maybe the new part supersedes the other? I may be getting too deep, but I wanted to bring it up.

I looked at the replacement procedure in the Service Manual and on YouTube videos for similar repairs. It is a straightforward replacement, but for me being a simple DIY-er, I'd rather leave it to an experienced mechanic due to the electrical components involved and cooling fluid lines being opened. Plus, I don't have the interface components to enter my car's computer.

So, with those points in mind, is this an honest diagnosis? Are the prices fair? Are there other inverter options available (refurbished/salvage)?

I can wait to have this repair done since I am currently telecommuting and can use other household vehicles in the meantime. But if I go with an independent shop, I'll be out $175 for the dealer's diagnosis.

 

Update 3: I called local mechanics that specialize in hybrids, all can do it for a significantly lower price for the part and labor (as with any repair when compared with a dealership). But, as pointed out already, a salvage part may be hard to come by; most are only able to obtain one by the beginning of next month at the earliest in my area. The dealer can get it done this week. I do have a road trip planned, so I decided to go with the dealership repair. Yes, it’s pricey, but I have emergency money saved up for a reason such as this. Though yes, a lower cost would have been better.

I was thinking, is there a risk when using a salvage inverter, especially if it’s from a vehicle with front end damage? I won’t know which one I’ll get. On a related note, during the service advisor’s initial inspection with me, he pointed out that the right fender attachment point to the vehicle frame was slightly off. This could indicate that my vehicle may have been involved in a collision and was repaired without going through insurance by the previous owner, hence not showing on the vehicle history report when I bought it. Could this suspected collision have been a factor in my inverter shorting years later?

Anyway, with this experience, I now have access to a great forum and contacts with local hybrid repair shops for the next repair (which I hope will be a very rare occurrence). This is my first major repair, and I was panicked; I had faith in Toyota’s reliability to not even think about such issues until this car gets much older, but then this happened. Thanks again to all for the great info and advice! I will update when I get the car back.

Thank you for clarifying the voltage reading and cable locations. I found the jump point in the engine bay. I’ll check the accessory battery and jump point voltages when I get the car back for extra assurance.

I did check the fluid levels of the car at the time of my initial diagnosis, all were on level and looking good. I did ask the service advisor about the inverter coolant since I know that it would have to be drained as part of the inverter replacement procedure, but there was no mention of a pump being the problem. I hope I don’t get a call during the repair that a bad pump was the root cause, and another item to replace… At least I’m getting a coolant change out of this, which I was planning to do myself at 100k miles. Now I just have to do the engine coolant.

 

I got my Prius c back from the service department with a shiny new inverter. The car works as usual and should last for a long time, fingers crossed…



I drove home and checked the auxiliary 12V battery, I’m getting a voltage of 12.5 now. I guess the accessory battery was stressed under the load of the inverter short, attempted restarts, and accessories running when I got the marginal 12.2 reading that day.

I was also able to keep the short-circuited inverter, mostly as proof that the job was done correctly. Could this still be refurbished despite the dealership claim that it cannot be done for a Prius c’s inverter? Maybe I can sell it? If not, I’ll probably drop it off at an e-waste collection center.