Which ELM dongle did you get? Not all of them are the same and some are literal garbage.
I went through 4 of them before finding one that actually worked. It was the one from Veepeak that finally worked.
Also needed Torque Pro, not the free version of the app.
Alternatively, you can get an OBDeleven as well.
EPC & limp mode will throw codes.
It would be cheaper for an independent mechanic to do it. But make sure they can do it right. If you bought a used brake accumulator and an independent mechanic who knew what they were doing could fix it... you could probably get it done for under a $1,000 if everything goes accordingly.
Also.... For the future so you aren't so unprepared, you can get yourself a Bluetooth Code Reader and use in conjunction with the Torque App to read codes.
If on Apple, you will need a A WiFi OBDII Code Reader or a more expensive Bluetooth OBDII Code Reader due to iOS using newer Bluetooth. You will also need to download a different Code reading App. Any reputable one will do.
You'll need to get it diagnosed.
It also sounds like your combination meter has failed as well. Extremely common failure on the Gen 2 Prius. There is a capacitor that needs to be replaced on the combination meter board as it wasn't engineered with degradation in mind. This was an oversight by Toyota... all Gen 2 combo meters will fail at some point.
Fixing the combo meter might fix you're non-starting issue but usually the combo meter not starting doesn't cause other problems.
Maybe you ran it low on gas too many times and damaged the fuel pump... lots of things it could be. But since the computers still turn on... start with getting codes read since it shows a check engine light.
For the future so you aren't so unprepared, you can get yourself a Bluetooth Code Reader and use in conjunction with the Torque App to read codes.
If on Apple, you will need a A WiFi OBDII Code Reader or a more expensive Bluetooth OBDII Code Reader due to iOS using newer Bluetooth. You will also need to download a different Code reading App. Any reputable one will do.
The Veepeak dongle w/ Torque Pro is what I used for years before moving to OBDeleven.
Torque Pro's gauges are better than OBDeleven's live data imo. So if you're wanting the gauges. This is the combo to go with.
Edit: you're IOS, F.
Here's an IOS alternative to Torque Pro. Do not know if the Veepeak works for that though. You'll have to do digging on that.
You need to get codes read/your issue diagnosed. If you want to destroy your car... keep doing what you're doing. Your Prius is suffering from a catastrophic failure condition.
My first guess would be intermitten inverter pump failure and your inverter is overheating as a result, causing the Red Triangle 🔺️ and emergency shutdown.
For the future so you aren't so unprepared, you can get yourself a Bluetooth Code Reader and use in conjunction with the Torque App to read codes.
If on Apple, you will need a A WiFi OBDII Code Reader or a more expensive Bluetooth OBDII Code Reader due to iOS using newer Bluetooth. You will also need to download a different a different Code reading App. Any reputable one will do.
$13 and it supports ' obd fusion' which is another app that's pretty useful. Veepeak Mini Bluetooth OBD II Scanner for Android, Auto Check Engine Light Code Reader Diagnostic Scan Tool Supports Torque Pro, OBD Fusion, Car Scanner App https://www.amazon.com/dp/B011NSX27A/ref=cm_sw_r_apan_glt_i_7YKXV0VTWY1PEFVHDPST?_encoding=UTF8&psc=1
What makes that one better than mine: https://www.amazon.com/dp/B011NSX27A/ref=cm_sw_r_cp_apa_glc_fabc_MQDWND9KYE6RB4M4Y0CR ?
For $13 and a free app (dr prius) I was able to kill that gawd dang reverse beep! I asked two dealerships about doing it, the first said that "toyota" had told them they aren't allowed to do it because it could open them up to liability. And the other had no problem doing it, for $75!
It sounds like you are having some strange issues. Codes again here would be helpful. The best thing to do at this point is to make sure you find someone competent to fix the issue.
If you can get the codes it'd be easier to make a suggestion. The Hybrid Battery fan running on high is something that does occur when the Hybrid Battery is failing... but again codes would be useful.
It is very strange in your last post that your codes showed low 12v voltage and speed sensor errors. I'm still of the opinion something deeper is going on electrically... like a loose 12v battery terminal. But impossible to say for sure over the internet.
For the future so you aren't so unprepared, you can get yourself a Bluetooth Code Reader and use in conjunction with the Torque App to read codes.
If on Apple, you will need a A WiFi OBDII Code Reader or a more expensive Bluetooth OBDII Code Reader due to iOS using newer Bluetooth. You will also need to download a different Code reading App. Any reputable one will do.