What a great car!

You're definitely on the track. The female connector you're missing is what's shown on the EWD as F4 and F5. If you click either one, it blinks, you click the button at the bottom, takes you to a page showing the connector shape, and pinout, and part number. In this case it turns out F4 and F5 are the same part number, you can have two of your very own for about seven bucks total.

But you also need the metal terminals to go into F4 and F5; I don't know any way to get those part numbers other than asking a real person at a Toyota parts counter. You give the part number for the connector housing (as just found above), and ask them to look up the terminals for it. You need four of those, of course. That's one reason you might just go to the dealer to buy everything, even if you might get the connectors a couple bucks cheaper online.

Then you need to cut four lengths of wire, crimp one of those terminals onto one end of each one, and assemble them into the F4 and F5 connectors you bought.

That leaves the other ends of those wires, which you have to route back to the instrument panel junction box where two of them will go into connector 3A at positions 36 and 37, and two into connector 3D at positions 24 and 25. You don't need to buy connectors 3A and 3D because they are already there, you'll just see they have no wires at those positions. You do need to look up the part numbers for 3A and 3D, just so you can ask your parts counter person to look up the metal terminals that go in those positions.

You crimp those terminals onto the other ends of your wires and assemble them into those not-yet-occupied positions of 3A and 3D, and plug 'em back in. Of course, follow the wiring diagram carefully, observing which wire goes to which pin number, and clicking the button to see the drawing of each connector and which pin # is where.

Have I given you enough of a start?

-Chap

 

Hmm, you're right that it's a pay site. On the other hand, if that actually meant you can't access it, then I wouldn't be able to either, right?

The two most DIY-friendly options are the two-days-for-$15 or the month-for-$75. I just bought a Gen 3 a few weeks ago, so I popped for the month and it has been very convenient as I learn about my car. Also it has made it very easy for me to look stuff up for other PriusChatters, but only until my month runs out. After that, I will probably only re-up when I have my own projects to work on ... but I'll hope to have given some other people a sense of what a valuable resource it is, compared to the $15 it takes to play.

Honestly, don't you see thread after thread in these forums where somebody is willing to spend dozens to hundreds of dollars to mod something they would rather light up blue than green? As the one secret ingredient that lets you do the job knowledgeably and confidently and safely, a techinfo signin is usually down in the spare-change part of the bill. Especially if you have a few projects you want to do, and plan them all out on one two-day $15 signin. What does that come to per project?

Probably not. Remember, one of 'em goes on the far side of the instrument panel. There's a lot of stuff packed in under there, and they like to have harness clips spaced pretty closely so the wiring doesn't shake around much. The 'location and routing' view in the wiring diagram will show you the path the factory wiring follows.

More than likely, Toyota just makes two different versions of the whole instrument panel harness, one that includes those circuits (and whatever else is in the higher-model Prius and not in yours) and one that does not. In principle you could swap out that whole harness, but you won't want to if you check the price, plus it would involve taking the panel out and unplugging/reconnecting every last thing in there that plugs into that harness.

Easier to just add a few wires you want.

Left end under the instrument panel. If it's like the Gen 3, the bottom edge of it is the instrument panel fuse block.

The only trick to finding it in the 'location and routing' view is that they categorize junction blocks under 'relay locations' for whatever reason. (It does, indeed, contain relays.)

If you need to take any panels off to reach the 3A and 3D connectors, the instructions will be easy to find in the repair manual, which you also have access to once you've signed in. It's just the 'RM' tab, instead of the 'EWD' (electrical wiring diagram) tab.

If such a bundle even existed, the 'other end' would still be bare terminals, you'd still have to unplug 3A and 3D, insert those terminals into the proper positions, and plug them back in. (For the record, the EWD section 'wiring harness repair introduction' is where it explains how those connectors unlock so you can fit new terminals in.)

I think it will all come together for you if you manage to shake $15 loose and spend some quality time with the diagrams.

-Chap

 

You'd get at it from the panel side. In my Gen 3 it is pretty easy to get a good view of by just popping out one small panel (which has one screw you can't see without popping out the driver's-left-foot kick panel first, which is held down at one end by the scuff plate, so 3 steps really). But I haven't spent any time looking at how the Gen 4 panel is put together, it's all different, but certainly something you could look up in a matter of minutes.

When you can see the connectors, to know the pin positions, you're going to want the drawings from the wiring diagram that show the connector shapes with the pin positions numbered. It might be that some of their connectors have numbers stamped in the plastic, but I wouldn't count on it, and if there are they are usually really tiny and hard to see.

-Chap

 

If you stick your head under there and find the instrument panel fuses, you are probably looking at the bottom edge of the junction box, so you'll know where it is.

Most of the wire harness connectors will be plugged into other surfaces of it (since the bottom edge is all fuses) and to see where they attach you will probably be removing at least one or two finish panels. It's always a little embarrassing to wrap up a project by replacing finish panels you broke (though they can be ordered from the dealer so it's not the end of the world, BTDT), and the repair manual is where you see how they come off correctly, so if you're going to try to do it improv, be really gentle and careful, especially if anything doesn't seem to be popping out the way you expect ....

-Chap

 

It turns into an interesting manufacturing optimization problem for them. On the one hand, it's an extra cost to them to have to maintain two different part numbers, two different inventories, two different specifications for their wire harness contractor, etc., and they could save that cost by just having one common part. On the other hand, they have to pay for the extra copper and terminals and connectors on every harness that includes circuits that won't be used, and the difference might only be a few dollars per harness actual cost ... but they're going to build hundreds of thousands of the things.

Sometimes it seems weird how they decide what to include and leave out in the different models (my Gen 3 model comes without foglights, but there's still an actual foglight relay in the junction box and the fuse is there, even though there's no wire from there to the bumper) but I'm pretty sure those 'weird' decisions actually get made by somebody wearing a green eyeshade and doing real math. Their contractor building the junction box probably quoted a much better price to just build one version, but the wire-harness contractor must have offered them meaningful savings to build two versions with and without the foglight wires, based on estimates of how many of each version would be sold.

-Chap

 

Hmm, well, I haven't got a 2016 of my own to go look at, but from what I saw in the manual you must be in the right neighborhood.

The owner's manual in your glove box should show you where the instrument panel fuses are. When you are looking up under the footwell, you should see a cover that is marked with fuse labels, and you can pop that cover off to see fuses. If you do that, you will have had your hand on the I/P J/B. It is a tall skinny box and the 'fuse panel' is the bottom edge of it.

-Chap

 

The bolt you see probably isn't the only one.

You might not have to move the junction box though. There are connections on most of the edges. The bottom edge is all fuses, as you see. The edge facing forward (against the firewall) is where the engine wiring and floor wiring plug in, there's probably no getting to those without moving the box, but you don't need to.

The edge facing the rear of the car is where the instrument panel connectors, including 3A and 3D, plug in, the ones you'd be concerned with. I am guessing as soon as you find how that section of the instrument panel plastic pops out, below and to the left of the steering wheel, you'll be looking right at the connectors you want. That's how it goes in my Gen 3. They do like to clamp the wiring harnesses very securely, so you'll probably need to loosen at least one clamp to have enough slack to unplug anything.

My techinfo subscription's used up for now, but that's where you can find the repair manual instructions on how the instrument panel plastic sections go together and come apart.

-Chap

 

Any tsb information shown /available for the gen 4?

LG-H901 ?