2012 Prius C2 No dash lights and doesn't start. Any help would be greatly appreciated

Hello all.
I am hoping that members of the forum will be able to help me with my 2012 Prius C. I purchased it new and it currently has about 59k miles on it. About 2-3 weeks ago my son was driving the car and got the engine light on the dashboard with the accompanying message to "pull over" and check the hybrid engine. He was a block from the house and after a few days he and I checked the car. It wouldn't start but the error message appeared on the dash. Following that we chose to check the two fuse boxes under the hood and then the fuse box under the driver's side. There were no obvious shorted fuses but after checking the inside fuses we tried to start the car again but not only did it not start but there are no longer any lights that appear on the dashboard.
I will add that about in February of this year we replaced the 12v battery at the dealership but did not experience any problems until receiving the error message about checking the engine. There is power to other electronic in the car, i.e. the radio, a/c, and interior lights. The key fob opens and locks the doors.
From the things that I've been able to find the common possibilities are the fuses, key fob, the 12v battery and the hybrid battery. My plan of action at this time is to change the fuses, the battery in the key fob, check the battery,clean the hybrid battery filter, to start. Following that, well, I am not sure.
It appears that my issues are not unique and I am hoping that members of the forum can suggest some relatively easy fix to at least get dashboard lights back on.
Any help would be greatly appreciated.

 

Thanks Bisco.
Update: I have slowly begun changing fuses and checking whatever I can.
I do want to share that today I found that Bussman low profile mini fuses fit perfectly within the passenger compartment fuse box for the 2012 Prius C 2.
I am hoping that I get to a point where I can get lights on the dashboard and at least start the vehicle - right now I'd have to be towed.
I'll periodically give an update in case anything I do currently may help others in the future.

 

I continue to read various posts from members and one referenced CARB standards. My understanding is that Prius C built to CARB standards have a warranty of 10 years/150k. I purchased the vehicle in New Jersey (CARB state) but now it is registered in Florida (non-CARB state). Can anyone tell me whether the hv battery is covered under CARB standards of Federal standards (8 years/100k)?

 

At this point I have changed all the fuses inside the driver's compartment and have attempted to jump start the battery. Nothing. I removed the battery to check the voltage with a multimeter and it measures 10.13 V. I realize that this is low but I think I should have been able to jump start the engine if the problem was only the 12v battery, not even clicking of the starter (if it is similar to other vehicles). Any ideas?
My next step is to check all of the fuses, etc. under the hood.

 

Update.
I have checked all the fuses with a multimeter and all check out fine.
I charged the 12v battery and attempted to start the vehicle. Still no luck. I have discovered through my readings that the Prius C does not have a starter or alternator in the same way a non-hybrid does so it explains why I haven't heard any "clicking" when attempting to start the car.
I do have dashboard lights, headlights, a/c, radio and emergency blinkers, as well as the "car" on the dashboard so I was either mistaken about my earlier thinking about no lights, or when I changed the fuses in the inside of the driver's compartment I did something to initiate the lights on the dashboard.
The buttons on the steering wheel appear to be functioning appropriately. I checked the hv battery fan mesh and it is clean.
The emergency blinkers work but the turning signals on the car do not. I don't know if the car has to be running for the signals to work but at this point they do not. I don't know if that is a clue to anything but it will be my next source of reading. In addition I will try to figure out my options with regard to the hv battery.

 

My periodic update.
Not much has changed since my last entry/sharing.
I am now trying to price out my options in anticipation of replacing my hv battery. What I have found is that for companies that will come to your residence and replace the battery with varying warranty(ies) is that each of the ones I have discovered do not do any diagnostic testing. One requires a printout from Toyota of the diagnostic code(s) and a second requires either the diagnostic evaluation from Toyota or your signature of a waiver stating that you request the company to sell you the reconditioned battery with the understanding that if the company installs the replacement and the car doesn't start that the company is not liable and that you made the decision to have the reconditioned battery installed w/o running diagnostics.
My next step is to have the car towed to Toyota for diagnostic eval either this week or after thanksgiving.

 

Thanks for your input Dubit.
It's very timely in that we just got back from the Toyota dealership.
According to the technician's notes there was noted to be corrosion in the smart unit and in the harness for the hv battery, and the recommended action is to replace the smart unit and hv battery. The estimate is a little over $3700.
Btw we asked about the warranty on a new hv battery and was told that it was 1 year.
We haven't made any decision(s) yet but I figured that I'd post the latest.
And again, thanks for your input Dubit.

 

First let me say that I hope that everyone had a Happy Thanksgiving time off.
And let me add that I very much appreciate the additional input from Tyler S. and dig4dirt (above), and in turn I went back to read the paperwork we received from the dealership's diagnostics and resulting dtc code(s) as well as other conversations that we had with them.

Just for reference, the dealer identified the following parts and total cost:
1. G9510-52031 - Battery Assembly (HV) 2456.74 + 1350.00 (core) = 3806.74
2. TOG9510-52031 - Battery core return - 13500.00
3. 89892-52011 - Battery sensor + 333.77
subtotal = 2790.51
Labor = 977.77
Total = 3711.28

Given that the battery sensor is bolted on the side of the hv battery (from what I can tell) with 3 bolts and with plug-in connections it certainly would seem to me to be an excessive labor cost, although I have to admit that I don't know what is done beyond changing the battery and sensor unit.
At that point I asked about warranty considerations since the warranty expired in March 2020 and that the car has less that 60K miles, and did not get a positive response.
When asked about the warranty on a new battery we were told that it is Toyota's nationwide policy to warrant new batteries for 1 (one) year.

DTC codes noted on the :
P0B42 - Hybrid battery voltage sensor B Circuit is low
P0B47 - Hybrid battery voltage sensor C Circuit is low

These readings led to checking the fuses, and they found that "found fuses out of place." The the service manager said they found the ignition fuse in backwards. I didn't know such a thing was possible but the car started and can now be driven, although we were told - it could last a week, a month, can't tell.

We were also told that there was corrosion in the battery sensor (Smart sensor) unit and harness (z9 connector?). I am assuming that that was a visual determination since when asked I was told that they do not open the battery.

In reading through the technician's notes I saw that for Circuits A-K it is noted that all are low but the pages look to be copies of the Toyota ESM (Electronic Service Manual) with only P0B47 highlighted (as identified above). There are also some additional page printouts called "monitor strategy" which continues to #3 - Replace Smart Unit and then #5 - Replace the HV Battery. But these are just pages on what I would call a decision tree based upon measurements, and nowhere is the dreaded P0A80 code.

I also have a copy of handwritten notes of the technician who appears to be in training as s/he is referencing taking action per "RM", who at one point has determined that the problem is the Smart Unit and "IF" problem persists then we would need a new HV. The notes then go on to identify that there is corrosion in the smart unit and in the harness for the HV battery.

I have some confidence that I need the Smart Unit and I have found that I can purchase one from any number of Toyota dealerships online for approximately 1/3 less than that noted in the estimate above. I will have to read up on doing it safely since the manual I have warns about high voltage with this part. At this the car can be driven although I have errors lights all over the dashboard as the dealership said they don't clear any dtcs until after they fix a car.

I have read in other threads in the Prius C forum that corrosion in the smart unit occurs in about 5% of batteries in Florida because of humidity; in other submissions I have read about early Prius C batteries where the harness attaches is sometimes mis-shaped and that leaking will eventually lead to corrosion. I am hoping that the corrosion is only in the smart unit as I assume that replacing the harness wasn't cost out because that would happen when/if I replace the hv battery. Otherwise I will venture into opening the battery case to look for corrosion and clean it out. Finally I have read one submission who references error codes, who replaced the smart unit and cleaned corrosion and said that the battery was fine afterwards.

To some extent I can understand why Toyota does not open the battery to clean corrosion although it would save me a significant amount of money; while at the same time I am incentivized to replace the smart unit.

As dig4dirt suggests I will try to contact Toyota Corp to see if I can get some assistance with costs, and I will balance considerations with a new battery/1 year warranty versus reconditioned battery with lifetime warranty. And in that vein let me also thank Tyler S. for sharing his personal experience with GreenBean as that is one of the companies that I am considering doing business with for this challenge.

Finally I have to thank all of the other individuals from who I reference and learned so much in my journey to fix the 2012 Prius C2.

 

I am hoping that not all are stealerships but am cautiously pessimistic.
Your words ring true dig4dirt.

 

I haven't updated in a few days primarily because I am contemplating my next actions. I am leaning towards changing the battery sensor myself as it is external to the hv battery and it appears that it mechanically it will not take much to unbolt and replace it with a new one; inspect where the corrosion is and how bad,, and see if I can clean it myself with compressed air; put everything back into place and see what dtcs I get and how the car runs. Right now the car does run except for a rare misfire of the ICE. What concerns me when reading the Toyota Service Manual concerning replacement of the battery sensor every step is noted to be dangerous because of high voltage. Otherwise I am good to go with replacing the sensor, checking the corrosion, and if necessary, opening the battery case and changing the harness(es) if necessary. Hopefully those actions will address whatever issues currently exist.
kenoarto, thanks for your input. Unfortunately I have not come across any coupons for 20% off service and our initial contacts with the dealerships for estimates showed minimal differences with total cost of battery replacement.
RobAustin, I appreciate your comments as well. If you don't mind let me ask you - do you find that there is as much concern about working with high voltage in replacing the hv battery? What did you do to minimize the dangers?