Retroplay

So, I wanted to relay some information I stumbled upon recently for those of us with pre-2006 SC's.

I had been watching eBay for a while for a Gen 4 nav screen and nac ECU at a specific price point. I found a monitor at a great deal and pounced on it.

The first tidbit is that if you plan to do this, you will need to make sure to get a monitor with the door assembly. The connections on the back of the monitor are not the same. You will not be able to swap your gen 4 monitor into the gen 3 door assembly. There is a mid-harness that connects from the back of the monitor to the door assembly and results in a different set of connectors. I believe those might be compatible. Also, to fully update to the gen4 system, you will need a map light assembly with the microphone and a microphone amplifier assembly. You will also need a different steering wheel control. At least the shell. Our steering wheel controls actually have the switches for the telephone in it, but the shell is missing the buttons. These seem to be a bit rare to find on eBay. Ongoing investigation here. I am in no hurry and these parts add up in cost pretty quick for experimenting. I will keep you updated.


So, now for the bonus. While researching the schematics and doing a teardown of the Gen 4 monitor for some reverse engineering, I stumbled upon info that our monitors are used in a 2003 RX400 SUV. I thought, surely an SUV would have a backup camera so I was curious how it was implemented with this system.

And what I discovered is that there is a camera ECU that converts the composite from the camera into the RGB for the monitor. It ties between the nav ECU and the monitor and switches the RGB from the NAV system to the camera when the car is put in reverse. This seemed a bit odd, since our monitors do have a composite input already. But anyway, I poked around a bit and found a camera ECU on ebay for $40 and picked it up for experimentation. Basically, for $40 (or whatever you can find the camera ecu going for), with some custom wiring, you will end up with something like a NAVIKs (NAVIK does this the same way as the camera ECU). It will convert composite video to the RGB used by our monitors. The reverse signal becomes a trigger to switch the video. In fact, you could grab an ecu and a camera from the RX400 and have an OEM backup camera.

The caveat is the connectors, of course. On ebay, you can sometimes find the ECUs with the cables plugged in (but wires cut). I usually try to buy those because the connectors themselves are hard to find. Looking at the wiring diagram for the RX400, it looks very possible to drop this into the SC430 and get an OEM backup system. Especially if you can find the harnesses (or rip them out at a junkyard). The same NAV ECU is used in the RX400, so the harness should make it plug and play-ish.

Anyway, the camera ECU is on the way and I will be experimenting with it in my testbench setup and will report what I find.

Just preliminary info for now, but here are some part numbers I found, if someone wants to experiment themselves:
86792-48101 COMPUTER, PARKING ASSIST - This is the camera ECU that converts the composite to RGB
86790-48060 RX400 CAMERA - the backup camera assembly

I haven't found the part number for the harness yet, but it appears from the wiring diagram that it all plugs into the NAV ECU in the trunk and shouldn't require any wiring through to the front of the car.

I have a number of projects I am bouncing back and forth with while working a crazy amount of hours, so no promises on how quickly I will update. Passing the info along in case someone with more time/money might want to jump in.

Retroplay

Along these lines, I wanted to mention that I am considering setting up a youtube channel to detail my experiments and how-tos as well as a patreon account if some feel inclined to support my efforts. My main concern is the pace at which I am able to do this. I have been reluctant to ask for donations because I know how busy with work I get and progress becomes very slow. But part of the slowness is due to funds. I typically need to buy two of each part I experiment with. I often need to destroy one to reverse engineer it and need one intact to finalize. This adds up really quick. I have probably spent 2-3K on parts over the last couple of years to build my test bench, not to mention equipment I needed to do these mods.

My goal is to set the above up by the end of the year. Just wanted to give a heads up. I want to start doing this all faster, but the only way I can do this is to ask for some help. I have a fellow engineer at work that is also starting to get interested in what I am doing, so I am trying to talk him into helping. Making some progress on that front.

Retroplay

A short list of my current on-going projects:

1. Reversing the LCDs in the radio and climate control (90% complete)
2. Increasing the brightness of the Instrument Cluster and possibly some major update to the cluster entirely (currently experimenting)
3. Universal ECUs. These will be drop in "after-market" ECUs that I envision can be programmed somewhat easily to develop new functions in the car. Imagine an arduino for the car. If it works out, this would support pretty much any Toyota (and possibly others if I implement CAN). This one will be hard to describe until I have something to demonstrate. Lots of software involved in this. Hardware has been worked out. Maybe 10-15% complete.
4. CarPC. Test bench is in progress (basically a simulation of the dash on a workbench.) This one will most likely be last because it depends a great deal on the development of the others. But I need the test bench finished before I can finish development of the others.
5. Tire-pressure monitoring system that actually lets you see the information about each tire (50% completed)
6. DVR/blackbox system that is integrated into our cars. Not started yet.
7. Wind deflector (the clear plastic piece near the rear window) display. Not started.
8. Hijacking the radio front panel and climate control (I'll explain this one later - I am only about 10% complete with this)
9. Cup-holder/Ashtray box upgrade
10. Third Brakelight upgrade. About 70% completed
11. Most of the above might necessitate a new gateway (not started, but working on reverse-engineering currently)

To give an example of scale, I need to spend about another $2K to finish the test bench.

If anyone has questions about the items above, just let me know.

bacardi11

iTrader: (1)

Retroplay
the work you are doing is unbelievable THANKS YOU

JohnnyCake

It's really unfortunate that the SC was not a high-volume vehicle cuz otherwise surely some of these ideas would be marketable.

When you set up a go-fund-me page, I'm in!

Retroplay

If the design is done right, the universal ECU could potentially be marketable since it would work with Toyota, Lexus, some Hondas, and if CAN were implemented, several other cars. I probably will implement CAN since our later model SCs do use it. The networks are designed to crossover and be able to talk to each other. The full details of that I have not 100% figured out yet, but if you had CAN in the car, you should be able to talk to the BEAN bus, for example. That is the purpose of the gateway in the car. It translates networks so they can all talk to each other this allows the techstream cable to program ECUs. It talks over ISO-9141-2 but using a J2534 application layer. It's all a bit complicated, but I think it can be simplified into something where someone doesn't need to know all the details.

Retroplay

I just received the Camera ECU just in time for the weekend. I've cracked it open to get a look at the hardware and holy crap is thing powerful. I think it is only used to display the backup camera with overlay for the guides, but it has a 32 bit microprocessor and an image processing chip capable of so much more, including MPEG2 playback. There are some unpopulated circuits that I think I can figure out that look like it adds audio capability including muting the other systems and taking over at least one speaker (similar to the way the NAV and telephone work). They apparently had more planned for this ECU.

Time to play

Bgw70

texsexlex

iTrader: (3)

....I wish I was closer also......most of the things he's talking about, is waaaay over my head....lol, but it's fascinating & interesting to know that someone can take a complicated system, disassemble it, retool it & make it better. If I were closer, you could have my car as a guinea pig !!! Count me in on the gofundme also

Zeropegleg

Wow, what a find. Retro-dewd! I've owned our 2004 SC430 for about 5 years and have been living with the stinking iPhone via monster tape playing contraption ever since. I actually thought I had blown the speakers in the doors for the last 2 years. As of late, I've only been using the radio to listen to NPR cause I hated listening to any music on the system. Turned out to just be my crappy monster-tape-aux-port-piece-of-crap thingy. the ML system is actually in good shape. I'm down for helping out in any way I can, I've been planning for an upgrade to the radio to go w/ a Pioneer XXXX-NEX to get Car-play as a baseline. But actually hated the idea of replacing the radio and leaving the crappy older 480i multi screen with useless antiquated GPS up there. I've been really wanting to pull off the same build you're looking at with the exception of adding multiple cameras. For camera's I really want 4K hoping to pull in some of my AI friends to see if we might be able to add some AI gesture capabilities like capture a known-user w/ bluetooth sensor as they're coming up to the car and perform facial recognition to provide something like 5x9's accuracy that Kurt is indeed Kurt. Open the car, top down and start the car w/ wave gestures. But really it all starts w/ the basics. Build the perfect Arduino interface to the IE bus, then move on. Keep it coming and send out the link for the gofundme. Don't be afraid to ask for help. A workman is worthy of his hire.

RichardMor

Retroplay, may I ask where you are at on the SC projects. I’m sorry I didn’t see this earlier and offer financial support. At a minimum, I am definitely interested in the RX400 backup camera.

thanks
Rich
Maple Valley, WA

Pumabot

Thank you all for the awesome guides and advise given here!
The screen on my nav unit is all cracked.
It is not the outside screen and looks to be in between two screens if that makes sense.
Ive searched the threads here and this sounds like it cant be fixed.
Can I swap the entire navigation head unit with a gen 4 unit if I also update the nav dvd drive in the trunk? Is it plug and play?
I understand the bluetooth will not work and Im good with that.
Also, I have no interest in an after market nav system.
Thanks!