Mechanic couldn't pull codes

I have posted about this prius before, on this thread. Well we drove it the 30 minutes home on the highway, managed to get it to 70mph comfortably, and the battery meter on the energy screen stayed green the whole time. We didn't notice anything mechanically wrong, except for maybe a bit of engine rumble. It was rhythmic like in time with something rotating. I am not a mechanic so I don't know how normal that is for the age/milage. I did take some pictures of the lights on, however, that I'm adding here.
So we took it to a parts shop that has a code reader and they found... nothing. Guy said maybe their meter is incompatible with a hybrid, not sure how true that is. I have scheduled an appointment with a dealer for 4/12/23 where they can hopefully tell me more.
In the meantime I'm hoping y'all can help me out! First of all, I don't know what some of these lights mean. Second, I'm fully prepared for the dealer to tell me the cell batteries are needing replacing, and once they said something is wrong with the electrical part that tells us the information (like the gas gage's actual reading, because it says full but only has a few gallons in it). But how much else should I prep for and what is necessary? We're limited on funds to fix the car up, so have to prioritize. My goal is to make it driveable for errands mainly. I'm a stay at home mom so don't need a vehicle, just something to get groceries and go to appointments.

Lights that are on: Red triangle, check engine, VSC and two circles with exclamation points that I think are for tires? There is also a red car with exclamation point on the display where the battery information is.
(please excuse the dirtiness in the pictures, it has sat unused for a good year or two and in need of desperate cleaning)

edit: forgot to mention the engine cooling fan in the backseat was on the whole time, at a steady pace that wasn't any louder than a normal AC at mid power.

 

Thanks for the info! My father in law previously owned the Prius and told me the fan was for the engine. But he is also not a mechanic (just a really book smart guy) so at this point I'm just taking what he says with a grain of salt.
I was just reading that OBD2 thread and noticed the Autel MaxiAp AP200. I can pick one up from Amazon for $60-70 and have it arrive in two days, and the dealer wants $75 for a full diagnostic (that goes towards repairs). Would it be worth getting a reader or just go ahead with the dealer's scan? I'm still looking the thread over to see what newer things are out there, but that one stuck out to me as something I could easily use.

 

I called my dad, who used to do all the work on his vehicles before he got too old (and cars got too labor-intensive), and went ahead and ordered a OBD2 reader. So hopefully sometime tomorrow I will have codes and the mystery of "what is wrong with the prius" will be solved!

 

Sorry about the delay in responding. I ended up buying an OBD2 reader and pulled the codes myself. It's the hybrid battery. It said it was cell 8, I believe, but recently a new code popped up that's just overall battery deterioration. My father in law, who has owned it for 10+ years (I'm not sure if he bought it used) says he never replaced the battery on the prius. So we're saving up to replace the battery, since that's cheaper than a new car, and have put it in storage until then.

 

It's definitely the battery. I've gotten some quotes for $1200-1500 self install so we are going to go that route.

 

I believe that price was for an OEM battery from a local dealer, but I don't recall seeing if it was refurbished or not. My search and calling around has been put on hold because my husband had a work injury that is putting a strain on our savings, and since he can't work/drive I have 24/7 access to our main vehicle. So I don't have to fix the prius right away. My memory of what I was getting quoted for is a bit off I'm sure.
If the difference is a few hundred, then yes we plan on going with brand new. But to be honest we aren't too concerned about longevity. I have this prius because it was rusting in my father in law's yard, and a deer totaled my reliable corolla. 2-3 years is all we want out of it, really. It's seen better days.

 

I may have got my numbers in my head mixed up and the $1200 was for an off brand/refurbished after the core return. I think the dealer was about $1600.
Either way, $400 more for peace of mind is worth it to me (and resale value would be higher). Before losing my corolla I was hoping to trade it in for a compact SUV, so I might end up falling in love with doing diy on this prius (and not having a monthly car payment).

 

Thanks for the advice! The dealer that actually inspected it a year or two ago quoted ~$2000, not sure if that included labor. But we are an hour away from Atlanta, which started this hybrid/electric program 2 years ago, so maybe that's why the dealers around there are quoting a little better right now.
Yeah we are looking to store it for a few months for now. I'm not sure if we would have a mouse problem (we have snakes in the yard) but I did once have one turn my corolla's air filter into a nest so I know that's a pain in the rear.