HYBRID SYSTEM WARNING LIGHT AND OTHER ISSUES

Hey everyone! Been having some problems lately, so here it goes...

It all started a couple months ago when I took a 4 hour road trip to do some camping. I got most of the way there, and suddenly when I stopped at the base of the mountain to get gas, about 50 miles to my destination, my brakes started grinding terribly. I was already a good 25 miles past the last auto parts place for me to get new brake pads and switch them out, so I figured I was just gonna go for it and fix the brakes once my trip was done.

Other than the horrible brakes, everything else was fine the rest of the way. It wasn't until the next morning, when I decided to drive down the mountain a bit to get breakfast...when I headed back up, my check engine light and hybrid system warning lights came on. I lost hybrid power, but was still able to drive, albeit only on the engine power.

The next day I drove back down the mountain, very slowly, and got the new brakes. Sure enough, it was metal on metal...don't know how I didn't hear any squealing or grinding before that, but there it was. Anyway, once I swapped out the brakes, the hybrid light went out and everything seemed back to normal.

A few days later, the hybrid light came back on, I lost hybrid power, and not only did the check engine light come on, but ALL my dash lights came on...every single one. I could still drive like before, but it concerned me. I thought, maybe I didn't attach the brake right and it triggered the hybrid light again. Anyway, I unplugged the hybrid and 12v batteries to reset the system, and everything seemingly went back to normal. Then again a week or so later, the hybrid light came on again, and I lost battery power. I reset it again, back to normal...another week and the light comes on again. I let it go for a week, and suddenly on Christmas, like a Christmas miracle, the system magically reset itself when I started my car on Christmas day, and it's been fine since.

On another note, I have been having an issue with acceleration that happened around the same time as the original problem. I don't remember exactly when it started, it could have been after this incident or in the days leading up to it, but it's become an increasing concern over the last couple of months.

I have noticed that there is a slipping or hitching feeling at times when accelerating. Typically once the gauge goes from hybrid power into gas...it's just the most sudden sluggish hitch. Similar to what it felt like when driving a non-hybrid when the transmission first starts to go out. A feeling like not enough gas is being fed into the engine, causing it not to accelerate smoothly. It typically does this a few times each time I drive now, especially now that we are in winter and it's gotten colder with each passing week.

I would rather not have to pay the dealership $130 just to run a diagnostic to tell me what they postulate the problem is, and considering I have been doing my best to fix my own repairs, I thought I would check with y'all for some insight as to what I need to work on.

A little history. I bought my 2010 base Prius from a private seller about 5 years ago. He bought it from the dealership as a former fleet car. It had 140k when I bought it, and it now has 244k. I have not done any major repairs or engine system cleaning as of yet, so I believe it may need some of these. Like transmission flush, power steering flush, coolant flush, etc. All I have done so far is replaced the spark plugs a couple years ago, along with the 12v. New struts I installed recently, new sway bars, and a couple rear wheel hub repairs.

Oh, another thing that happened two nights ago that was a concern. I started my car, and after a few minutes of warming up, a loud revving/whining sound came from the engine compartment...I have never heard this sound before, and it immediately concerned me. I killed the power, but the sound kept going for a good 3 seconds after and then stopped. Thankfully it has not made that sound since, though I feel it is connected to whatever is causing the acceleration problem.

Okay, that's about all I can think of right now. If anyone has experience that could give me insight as to what I can focus on next, I would really appreciate it. Love you guys!