2006 Prius, Error Codes C1241, C1256, C1391

Hello! So I have been following this website for a while ever since getting my 2006 Prius just about 2 years ago. I'm am currently running into an issue regarding the ABS, VSC, and (!) lights. My braking system seems to be malfunctioning (the regenerative portion of it anyways-- the braking is "weak" which seems to suggest that the regenerative braking technology is disabled). Ever since these dash lights have come on about two weeks ago, I haven't driven the car at all, but have turned it on every few days just to top up the batteries and such. I am a full-time student and live really close to campus so it hasn't been TOO much of an issue since I can just bike everywhere, though it is definitely a nuisance, and come potential internships could pose a big problem.

I downloaded/installed Techstream (ver. 14.00.018) today and read my codes with a compatible J2534 OBDII-to-USB connector and was able to get the C1241, C1256, and C1391 out of the ABS/VSC/TRAC ECUs. I saved some freeze-frame data from Techstream associated with the C1242 and C1256 readouts which I have attached below (photos). I also saved out the freeze-frame data in a .TSE file but honestly, am new to Techstream and don't really know how to view this file's information (seems to be encrypted Notepad). I can e-mail it or whatever if it helps and provides insight additional to what it provided by the photos.

I'm wondering if anybody has had similar issues or has any additional insight into how I could go about solving this problem? Thanks so much!

 

I was hoping that wasn't the case but it did seem that all signs were pointing to it. Regarding the repair, two things:

1) Is it possible to see if my car has already been serviced for the recall, and if so how? I purchased it used in Orlando. This might help to rule out the accumulator or maybe allow me to get a new one free if the recalled item was faulty (I would imagine?).

2) Regarding the recall, what is the information of the faulty part compared to the recalled part which was used to replace it? If possible I'd like to ensure that the replacement part that I get for it is the same as the recall part so that I don't have to deal with an additional failure shortly after.

Thanks for the response by the way!

 

What should the voltage values be for the IG1, IG2, BS1, BS2, +B1, and +B2 processes?

I tried taking a voltage reading the other day using my min/max function and got 12.46V low/ 14.0V high I believe, however I'll take new reading later today around 3pm EST. The 12.46V seemed sketchy to me because I'm pretty sure it was also my sitting voltage across the 12V battery with everything turned off, so it seemed obscure that there would be no drop upon being turned on. It makes me think that I was either using my multimeter wrong or that it was unable to detect a voltage minimum spikes which maybe occured very quickly on startup (assuming that's an issue some multimeters can have).

On that note, I did just get myself a multimeter because I figured it made no sense to have a Prius without one lol, so I definitely wouldn't mind checking these voltages and trying to find a cause there, assuming I have reasonable access to these cables.

It's worth mentioning, maybe, that I haven't heard weird screeches and such from my actuator pump in my hood before the problem showed up, or even now. My car still turns on and is silent, aside from the lights. There was a high pitched warning beep that would come on occasionally and then turn off after like 5s, but it doesn't happen all the time.

 

I read the voltage across the 12V again after it had been at rest (and measured at night in roughly 70°F weather) and got an at-rest reading of 12.4V, and a low reading of 11.9V and a high of 14.0V during the startup. Is 11.9V pushing it? I cleared the codes and it seems to be running fine, though I only ran it for a few minutes. Lights are gone though... For now. I'm going to drive it around the block repeatedly in a little bit to get some cycling going through the HV battery since it's been sitting around for a bit, and also to test and see if the lights come back on in a reasonably safe manner.

 

Are these terminals accessible from the inside of the car on the driver's side by any chance, or perhaps their connector cables? I didn't mention this because I didn't think it relevant, however I had also had a black combo meter issue back in the fall semester (where my combo meter lights such as my odometer etc weren't appearing). I had removed my combo meter myself after opening my dash, sent it to a repair person through eBay, and got it back functional. I reinstalled it myself as well and haven't had any issues until now (about half a year later). I'm beginning to wonder if maybe there is a cable which connects to the brake ECU under the dash which may have accidentally been left loose. Any idea if there is? Thinking I might open the dash back up and check my cables there if so.