Auto-folding mirrors and turn indicators part numbers

FYI: Not a big surprise, but the mirror covers from the Crown don't fit the Prius. The overall shape is identical, but the interior latching points are different. Would have been a pretty cheap way to get body matching mirror covers for owners of red Priuses.

 

I doubt anyone else is planning on doing this upgrade, but I'm stalled for the moment and won't be updating this for a few months. My next step is going to have to be pulling the dash, and I don't have a warm space to do it and I'll have to be able to get it done quickly since this is my only car. Temps around here are dropping well below freezing and will stay that way until March or April.

I pulled out my passenger door wiring harness and added everything I needed, but (as expected) there are no matching wires leading from the footwell connectors up to the left and right junction controllers deep in the dash. From there, wires might be needed to go from the junction controllers to the power distribution box assembly that's attached to the main body ECU behind the dash between the steering column and the driver door. Won't know what is already there and what needs to be added until I actually get in there and check.

Regardless, there are wires that need to go from the driver footwell to the passenger junction controller and from the passenger footwell to the driver junction controller. With that much work to be done, it just makes sense to pull the entire dash cover to get access to the main instrument panel wiring harness. That will take it from a near impossible job to a fairly difficult one. It will also make it easier to run the remaining wires I need for my projection illumination kit(shines the Prius logo on the ground when either front door is opened) and the reverse linked passenger mirror(which almost certainly isn't going to work anyway).


I've gone too far to stop now, but I'm to the point where I wouldn't recommend this project to anyone else unless they love automotive wiring. The parts are relatively easy to procure and install; the actual wiring is a cast iron bitch.



For those that are morbidly fascinated with crap like this, I'll attach the wiring location diagrams just to show where the wires will need to be run.

OK2(driver footwell) to K115(passenger No. 10 junction controller) - 2 wires
OK2 to K25(driver No. 6 junction controller) - 1 wire

NK1(pass footwell) to K115 - 2 wires
NK1 to K25 - 1 wire

K115 to K21(power distribution box assembly) - 2 wires (might not be needed)

K25 to K19(Combination Meter Assembly - aka the main MFD) - 2 wires (almost certainly not needed)

 

Getting closer to restarting this project. Going to get a week of temps in the 50s and 60s. But I ordered some parts that may or may not arrive before the temps slide back into the 40s for a couple weeks. (I decided to do the dash LED color change while I've got the dash apart.)

Anyway, I want to give a warning to any other fools considering this project. I've been poring over the wiring diagrams even more, and I've become very worried the folding mirrors will never work. At least not OEM style.

To make the mirrors fold, the main body ECU sends a signal into the Power Distribution Box Assembly, where it goes through a pair of relays before making it's way out to a junction controller and then to the footwell. What I'm worried about is whether the PDBA actually has the relays inside that I need. Without those relays, I think I'm dead in the water on the folding mirror portion.

I don't foresee any problems with the turn signal indicators. The power from those branch off a junction controller that supplies power to the rear taillight assemblies. That part should be a breeze.

Worst comes to worst, I'll leave the folding motors disconnected and just live with the turn signals operating. With the motors inside, the mirrors still function about the same as the standard mirrors when you fold them manually. I suppose I could try to jury-rig some sort of aftermarket relays and switch, but I don't like the idea of cutting a hole in the door or dash to mount the switch. (The OEM mirror-folding switch I installed that's part of the door won't work for that because it sends a digital signal to the ECU to have it fold the mirrors.) And there'd be no chance of doing auto-folding mirrors unless I paid someone to do the wiring, as I don't have that level of skill to design the system from scratch.


To see what a Power Distribution Box looks like and what it does, TheCarCareNut had to replace one in a brand new Tacoma because the owner installed some aftermarket LED taillights with a crappy internal fuse that ending up pulling way too much power and burnt out a part of the PDBA. (I really wish he had made this video before I started ordering parts for this project last year. )

 

If all you need to do is swap the turn signals, it's pretty easy.

1. Pop off the mirror glass, being careful to not rip the heating element and BSM connectors off. Disconnect the two connectors from the mirror.
2. With the help of a small screwdriver or other pry tool, pop loose the tabs on the upper half of the mirror behind where the mirror glass used to be. This will help free the mirror cover, which you will pull straight forward to release.
3. To remove the lower mirror cover, start by looking straight down at the newly exposed inner mirror and at the area closest and furthest from the car. You will find the lower mirror cover clips together with the mirror body at those points. Start at one and work your way around; including the lower half of the mirror from step 2. If you have the 360 cameras, be careful when pulling the lower cover away as you don't want to pull any wires free.
4. At this point, you'll have access to the two screws that hold the turn signal to the mirror body. Swap the parts and reverse order for reassembly.

I'll attach the relevant Repair Manual documents. It will probably take you up to an hour the first time you do it, but it becomes much easier with practice. I'm probably down to about 10min, and I am not proud of that fact(because it means I've had to disassemble and reassemble the mirrors more times than I want to count - lol).

Reading order:
1. Remove Outer Mirror Glass
2. Remove Outer Mirror Cover
3. Disassemble Outer Mirror (only step 3 or 4 depending on whether you have 360 cameras)
4. Remove Side Turn Signal

Have fun.

 

Well, the moment of truth is coming soon for my mirror project. The right side of the car is almost completely done. I still have to install the projection light in the door and run the wire for the back seat footwell, but the heavy lifting is done over there.

I've currently got the wires run from the right side of the dash to the left. (8 wires total, bundled in loom) I'm just taking a quick break from wiring the left side of the dash. 4 of the wires will go into the power distribution box area, and 4 will continue down to the driver footwell. Once the first four are connected, the passenger mirror should be able to fold and the turn signal should work.

I've gone back and forth so many times on betting with myself whether it's all going to work. At first I thought it was going to be easy, then I discovered it was going to be very hard(when I realized the wiring wasn't there), then I became convinced the folding mirrors would never work, and now I'm finally confident it's all going to work once I make these last connections and put everything back enough to start the car.

I was very worried a few months ago because I saw the folding mirrors required a pair of relays inside the power distribution box. I figured they wouldn't be there for US/Canada cars. After a couple months of pessimism, I finally got smart enough to check part numbers for the PDBA and compare the US, Europe, and Japan versions. It was a huge relief to discover they basically all use the same PDBA. So the folding mirror relays have to be there in the US/Canada models.

All the mods I'm doing:
1. Turn indicators in both side mirrors
2. Power folding motors in both side mirrors(includes auto folding on lock/unlock)
3. Projection illumination on both front doors to light the area where you put your feet as you exit the car
4. Rear seat footwell lights tied into the front seat footwell lights so they behave the same
5. Reverse-linked passenger mirror to make seeing the back corner of the passenger side easier
- don't expect this one to work because it was meant for a RHD car - super easy to disconnect if it pivots the mirror the wrong way

Finished mods
- spare tire conversion
- body-color side mirror caps

To do list
- upgrade horn to high/low Lexus pair (have the kit, just need to install it)
- door sill protectors(also have the kit, just need to install)

 

Quick update: They work. <sigh of relief>

Only passenger door for the moment, but the drivers door will work when I finish wiring it. At least I've finally proven the concept works after a year of research, planning, and slow labor. The turn indicator works just like it should, and the mirror retracts and extends when the doors are locked and unlocked. No reprogramming of any type was needed. The mirror currently doesn't retract/extend when the button on the armrest is pushed, so I'm going to have to dig into that. See if there's some wiring missing, or maybe the ECU just isn't programmed to listen for a command from the armrest buttons. But as long as the auto-fold function is working, I'm happy for now.

The reverse-linked mirror even seems to be working correctly. It needs to be calibrated, but I've got the instructions for that thanks to google translate. lol


I'll post a video when I'm closer to being done, as well as filming at dusk/night so the lighting will be more visible.

 

Going to be about a week. I found out I need to add some more wires to make the mirror buttons work. I've got the wire and most of the terminals I need, but I need two I don't have. I ordered them tonight from DigiKey, but they probably won't get here until early next week.



Two little connectors. Order them from my local Toyota dealership and they'll cost over $60 for the two, but they'll be here really quicklyvv and be confident they're the correct part. Order from Lewis and they'll be around $40 and take several more days. Order from AliExpress and be sure they're the correct part and they'll only be $5 for 10(including shipping), but they'll take 2-3 weeks. Order from DigiKey and hope they're the correct part, but they only cost $9 for 10(including shipping) and should be here in a few days.

 

Oh, yeah. To both those questions. lol

Technically, you wouldn't have to remove the dash to do the job, but there are two good reasons to do it. First, it allows you to run all the wires from one side of the car to the other along the main instrument panel wiring harness instead of just zip-tying them underneath the dash wherever you can; makes for a much neater and professional job.

But possibly the bigger reason is because it makes it so much easier to access the junction connection holders and the main body ECU/power distribution box assembly. You end up working with these tiny terminals and 22-24ga wire. You're stripping the wire, crimping on the terminals and splices, and re-pinning the connectors in some really cramped spaces. It's fairly difficult to do with the dash out, so I can't imagine how tough it would be with the dash in and restricting access to those areas by 50-80%.

I got interrupted by a friend's project, so I've been driving around without a dash for better part of a month. The only things hooked up are the steering wheel and stalks, the shifter, the power button, the fuel door release(only reconnected that when I needed to fill up), the portion of the center console with the E-brake switch(cruise control doesn't work without it), and the combination meter(the "gauges/speedo" screen). And even the combination meter is just laying up there; not bolted in or anything. lol

I discovered just after I pulled the dash that you can drive around town with only the steering wheel, stalks, shifter, and power button installed. The car's not happy about it, but it'll do it. I hooked up the combination meter so I could drive on the highway(need to know my speed), and the E-brake switch so I could use cruise control.


I got the last connectors I needed in the mail yesterday afternoon, but the last couple days have been pretty hot(heat index in the 90s). Tomorrow is supposed to be in the low 70s, so I need to get off my butt and start wrapping this thing up. I'm 95% certain the button in the door to fold the mirrors will work once I run these last extra wires(it's what I needed these last connectors for), but I'm pretty sure the reverse-linked mirror is a loss. It was meant to be installed on the LH side, and think there are physical reasons it won't work on the RH side. Oh well, I've got the 360 camera option, so it's not a big deal.

I'll take some photos tomorrow of the different areas before I start buttoning things up.