P3125 and no start, 2003 Prius

For any project Prius bought in brick condition, you're definitely going to want a scan tool (whether Techstream or some equally-functional alternative, if there is one) that can show you all of the codes and subcodes, freeze frames and live data lists.

P3125, if I remember right, is a gen 1 code for anything involving the inverter/converter, and has something like a gazillion different subcodes distinguishing the actual problem. (By the time later generations came out, the SAE had created a whole bunch of different standard P0 codes for different inverter/converter issues, and Toyota retired the P3125 code and assigned all those different issues the gazillion different P0 codes that were newly standardized.)

 

The two Gen1 PID files for Torque Pro that are/were floating around had a couple of typos, at least back in 2018.

This post has links to the two PID files: Torque PIDs for Gen1 Prius | PriusChat

This post explains the typos I fixed: Scangauge or Torque App? | Page 7 | PriusChat

Once I fixed those, the then-current Torque Pro could talk to my 2001, through one of those generic Bluetooth OBD-II scanners.

I once thought as you do. Get Techstream.

A safe next step would be getting Techstream.

If you want to try charging the modules in situ, I would disconnect the 12 volt battery, remove the service plug from the HV battery, unplug that orange connector from the battery ECU, and disconnect the two main cables from the HV battery. This makes it so the module stack is definitely disconnected from anything else, so your charger won't send voltage into any strange places. Make sure you trust the limits/shutoffs in your charger, and check on it often.

It doesn't take a lot. When I first got Techstream in 2018, I ran it on a desktop PC that was the Wal-Mart Black Friday special in 2004. It had XP patched up through the end of support, Athlon XP 2.0 GHz, and 0.5 GB of memory.

It was a pain in the butt to haul the PC and monitor out to the car, but it ran Techstream. Yes, I almost drove off once without unplugging the 120 volt extension cord for the PC and monitor first. >_>

I did try one of those "active" USB extender cables so I didn't have to schlep the computer around, but I couldn't get it to work with the OBDII-to-USB cable. It did work with some other stuff, like a thumb drive and a webcam - just not the OBDII cable.

Now I run Techstream on an old Acer laptop that somebody gave me. It has Windows 8.1, 64-bit. There is an extra dance to do to get the 64-bit driver for the USB cable installed, but it works.

I have never tried to run Techstream on Windows 10 or 11. If I had to use one of those, I'd probably try 10.

Whatever OS you have, you will need Java. I used Java SE 6 on XP, and something newer (not sure exactly what) on 8.1. You can download old Java versions directly from Oracle after you make a free account.

You also need a "Mini-VCI" OBDII-to-USB cable, which should be available on Amazon. I'm not aware of any Bluetooth adapters that work with Techstream.

The post I made when I initially got it working is here: Attempting to get our original 01 Prius back on the road | PriusChat

In general, @ChapmanF is right about P3125. I stopped counting at 70 sub-codes in the factory manual. Some of the sub-codes are as simple as a open circuit in one of the data buses to the inverter (mice chewing on wires?) and some are an immediate "replace inverter/converter assembly".

You probably know this, but the inverter/converter is that big square box under the hood that says "Toyota Hybrid System" on top. In the absence of a more specific trouble code, it might be worthwhile to get a strong light and inspect the low-voltage harnesses coming out of it, as far as you can with everything installed, to see if there are any beat-up places, bare copper showing, etc.

At least a few years ago, you could get PDFs of the factory manual from Toyota, for a price. The site was (is?) run by Snap-On; it offered a one or two-day subscription for like $10. Unfortunately, it comes as a couple of thousand individual PDFs, and at least back then, there was no "download all as ZIP" option. I can't remember if it was scraper-resistant or not; I do remember it took a couple of hours to get them all.

 

The access options for the Toyota manuals are described on this page:

Toyota Service Information and Where To Find It | PriusChat

If you are signed in to the Technical Information Service, there is a whole lot of information there; not just the manuals, but service bulletins, quick technical guides, course materials for the Toyota technician trainings, and so on.

A lot of those things are straight downloadable PDFs, but the manuals aren't (except the legacy ones for older models). They're just straight HTML web pages with images. You can click your browser's "Print to PDF" to save PDFs of the manuals, but that's a whole lot of clicking if you want to save a several-thousand-page manual.

The online pages have a lot of cross-reference links. One procedure might say something like "Remove intake manifold [INFO]" and you can click the link to go to the manifold removal steps. After "Print to PDF" you end up with a bunch of blue [INFO] boxes that don't take you anywhere, so that's less convenient.

The online wiring diagrams are nicely interactive: you can click on one component, say, and the circuit it's in gets highlighted and you can follow it around between different views, pull up the connector part numbers, and so on. It has download-PDF links, which end up giving you a different, PDF-formatted version that is essentially the same as how the old paper versions looked.

The two-day subscription has not been $10 for a while now; as of today I think it's $25.

 

...like the Gen1, which we talk about here in the Gen1 forum.

For a Gen1, the PDFs you can directly download also have links in them, but they assume that you save them on your local drive in the same directory structure that the web site uses. (They're relative links to local files - they don't refer back to the Web site - so they will work if you keep the directory structure.) The few I checked just now also have the page numbers in the paper manual with the link, so you can probably navigate to the right PDF on your own.

When I had the short-time access, I looked up a couple of pages from the 2010 Prius manual, because someone I know has one. I found the functionality you described. I looked at trying to scrape it, but there was a lot of Javascript - partly to implement the neat features, and partly, I think, to make it hard to scrape. >_>

Looking at the timestamps, I bought the access and downloaded the 2001 manual in December 2018.

 

I'm thinking it was $20 around that time.

 

Yeah, I got an ugly bootleg on the Service manual - pages missing and not always in order. The Electrical manual I found is in a lot better shape, but as Mr.R said, the links don't work. I have to use the Find Text tool a lot.

But both work for what I need, for what they can do. I would definitely recommend Techstream. I have a copy and the cable, but no clue where to begin loading XP on something. If I had an XP, I could probably do it, lol.

 

Dang, Skeptic - where are you in CO? I have a car in storage there that I may part out. No reason to except I don't wanna pay storage.