Multiple Issues, PLEASE HELP

I know that some of these issues have been discussed multiple times but want some input specifically for my situation if possible.

2004 with 179500 miles. This is my mother's car who is very disabled and on fixed income

Winter of 2016, noticed the coolant ran low / out somehow and refilled it after temp gauge alarm lit up.. No problems after that

12v battery was dying around christmas 2017 and was selectively jumped with a jump box a handful of times to get to an appointment or store here and there when my sister and her husband was not available...

Battery completely died beginning of this year where it wouldn't hold a charge, period....

When I finally got a chance (and my mom's sister helped pay for the repairs) last week, after the vehicle has sat for months essentially. I jumped the car and noticed the red triangle on the cluster, VSC, ((!)) Check Engine Light (which i took to autozone and came back to P1150) and on the HUD the red car silhouette with ! inside of it...

Dropped off at toyota dealership and got back the next day they said they replaced the battery but they notated that the hybrid battery is failing.

Upon driving the vehicle I noticed the battery levels wildly fluctuate, and often stay down near one or two ticks, sometimes it'll go to full, but at a stop light the ICE doesn't want to turn off, sometimes sounds like it's sputtering at a really low idle, and won't go to what my mother calls "Stealth mode" (lol), the battery will rapidly drop to 3 ticks, engine fires up faster, jumps right back up, and repeats...

It is now going to limp mode more often than not, but not really any specific time, happens more the more i hit the accelerator, like when it's taken over I-64 and Afton Mountain which is a fairly steep grade.. The Energy Monitor completely goes blank, no pathing of energy anywhere, the rpm sounds like it is being halfway floored, no acceleration over 25 mph, and i have to pull over, shut the car off and restart it to get the thing working again...

I checked with the vehicle on but not started, the inverter coolant pump is humming, both audibly and with physical touch, however no coolant is circulating in the reservoir next to the inverter/motor whatever that big steel box is next to the engine

My thoughts are this...

The Inverter Pump, which was replaced under warranty / recall in 2011 is humming i feel it vibrating, sounds like to me it's running just fine... no churning in the reservoir indicates a clog or air trapped... Could this be the case? Especially if the coolant ran low two years ago?

Why the VSC / ((!)) lights? Toyota adamantly states that they reset the codes but came right back (all while sitting in the tech bay, hmmm)

Toyota stated they pressure tested the coolant system since one of the receptacles (not mentioned) was empty and it came back to no leaks... two days later when brought back they said the radiator is leaking, yet I drove it and can find no leaks, and no lost fluid... (Compression seems good, no head gasket issues that I see)

Summary:

Vehicle is going to limp mode
Hybrid Battery won't hold a charge
12v was just replaced after being used WAY too much
Vehicle has an off voltage of 12 volts, and an on voltage of 14.4 as it should.
Inverter pump FEELS like it's running but no churning
The cooling fan for the Hybrid BAttery sounds nosier than usual, not like bad bearings, but running faster... Though I haven't driven the car in about a year and maybe just poor memory

Was going to say the coolant system should be bled, i saw hookin ga hose to the bleeder valve opened by 10mm wrench in front of the inverter/motor then running it to a full reservoir next to it, then double tapping the power / start button without the brake depressed, and let run for about 10 minutes keeping an eye on the level...

How can I clear the codes out of the ECU / BCM myself if i don't have a scangauge or specialty toyota tool?

Any other thoughts on what I should go for next or try?

I'm convinced the Toyota dealership is a con artist and took advantage of my mother and sister (who also has severe mental impairment)

Thanks
- Sean Feehan

 

Not sure why the coolant was low, it was flushed and thermostat was proactively replaced about two years prior, however it was NOT with toyota brand coolant...

Also, checked again when i wasn't half-asleep before work, the inverter reservoir IS churning, looks like that is all working as intended, sorry for misinformation earlier...

the battery is brand new optima yellow top IIRC what my mother said the dealer put in.. I'll take your advice to heart, awfully concerning a brand new battery would give that, bear in mind I read the voltages through the onboard HUD by holding info and flicking the headlights as i read somewhere here in the boards

Will pop the neg off the terminal, right underneath the rear cargo liner right underneath the passenger rear taillight assembly? Will that clear ALL codes, including hybrid codes, vsc, and ((!))?

Very possible....

Thanks so much for your help. I just wasn't sure if there was any way to save this hybrid battery... It sat for so long I guess it just crapped the bed??

I was reading the refurbs for about 800-900 are only good for maybe a year or so? Is this still true??? It's much more feasible for my mother to possibly fix this (with the help of her rather wealthy sister) I can do the work required, seems pretty easy, just a bit tedious getting all the panels removed to access the battery.

 

Do you have a good link to a recommended one? I've never contemplated or considered rebuilding it, but watched youtube to replace it, having some experience in mechanics it looks pretty easy, just tedious. I know the search feature will yield me more than a few, but wasn't sure if you had a hotlink to one you recommend personally.