Least-obtrusive way to get Android Auto/CarPlay in a GZG50 Century

[pugwonk]

I got wireless Android Auto running through the standard front screen of the Century! Lots still to do - no touch screen, no backup camera, audio is terrible, and the stuff is all piled in the passenger seat. I need to find connections that will allow it to switch into night mode, and tell when reverse is engaged, and sadly neither of those signals appear to be in the video connector. Maybe the 6-pin plug for the gear shifter?

If anyone else has any ideas about the nearest place to the gear shifter with a +12V for lights and a +12V for reverse, please let me know!

Another piece of the puzzle that I've made some progress on is getting rid of the TV channel selection buttons. The Century shows 6 blue TV channel selector blue buttons on the screen when you switch to VCR but, when you play a video tape, those buttons disappear. I was hoping that this signal was sent somewhat simply down the 14-pin VCR cable. I was in luck... pin 14 went from 0v to 2.1v when a tape was played. Rather handily, pin 13 stays constantly at 2.1v when the ignition is on, so I just wired pin 13 into 14. Now the car constantly thinks that a videotape is being played, so it doesn't show the TV channel selectors on the screen. Unfortunately, this also means that the car thinks a video is being played, so whenever you go to play a CD, or the radio, the car instantly switches back to my AA screen and doesn't play anything. If I was going to be really anal about this then I would work out where that signal comes from, and politely shut down my AA box when the Century tells the video player to stop. I'm enjoying this project, so I'm going to try and do that.

I will have an "off" switch hidden somewhere for the whole system, but it would be great if I didn't need it.

The next step is going to be fixing the audio. It is really bad - lots of hums and strange beeps and crescendos that are almost as loud as the music. It never did this when it was playing VHS tapes, so I'm sure it's something I've done. A friend told me that it was very unlikely that chassis ground was also audio ground, and right now I'm using chassis ground for audio/video ground. I suspect that AV grounds are somewhere in the set of black wires that seem to do nothing, but I think the best way to find out is probably just to try each one and see how the sound is.

I'm very pleased with the progress today - at this point I know I can make something that will do adequately for navigation, and that's the thing I want the most. However, I also really want to play music through it, and right now that sounds terrible.

[GameHunter]

Super impressive undertaking! I would be following in your footsteps if I could, but I am waiting for the 2000 model year interior refresh as the screen is bigger in the rear and front. It also is slightly higher resolution. 2025 can't come soon enough lol. Saw someone who had a 2000+ model century that had it plumbed into the system nicely.

[pugwonk]

Super impressive undertaking! I would be following in your footsteps if I could, but I am waiting for the 2000 model year interior refresh as the screen is bigger in the rear and front. It also is slightly higher resolution. 2025 can't come soon enough lol. Saw someone who had a 2000+ model century that had it plumbed into the system nicely.

thank you! Do you know how the person plumbed it into a 2000 model? So far all of the solutions I've seen involve going putting a TV modulator onto the antenna in the trunk and I'm a little bit suspicious that the audio isn't going to be great through there (I had a similar solution in another car and the audio wasn't all that good).

Of course, the audio is absolutely terrible with my wiring at the moment, so I can't really talk...

[GameHunter]

thank you! Do you know how the person plumbed it into a 2000 model? So far all of the solutions I've seen involve going putting a TV modulator onto the antenna in the trunk and I'm a little bit suspicious that the audio isn't going to be great through there (I had a similar solution in another car and the audio wasn't all that good).

Of course, the audio is absolutely terrible with my wiring at the moment, so I can't really talk...

Just was able to message them actually!(thanks internet!) it was a 2006 model that I was viewing in the video apparently. Very interesting but their implementation while works, may have been less plug and play as they mentioned needed to modify the digitizer… not my preference.

I also dove way into the different years and the nav units and screens…

2000-2004 had what appears to be a “gen2/3” Toyota/lexus units

2005-2017 appears to be gen4+ but may have never had more. I don’t even know if Bluetooth audio was ever supported. 2010 manual suggests it was never a thought.

I went and looked up the part numbers for the nav computers and radios so I could see the correct connections on the back of them…

I kid you not, the navigation computer(which holds the nav dvd) out of the 2000 century has identical connections to the 2001 ls 430 and 2001 gs 300. So in my opinion it is theoretically possible to swap that computer in. In fact, I’d go as far to say, it could be even possible to swap in the updated 2005 Prius computer for a gen4 implementation just minus the Bluetooth calling, and that would get you up 2015 US maps(given you hav the DVD, for aesthetic purposes lol!

The actual screen assembly(varying in visual style/buttons) in the century(2000-2005), the ls 430(2001-2003), and the gs300/400/430(2001-2005) have identical connections as well. The power harness coming off the back of the actual radio controls in the 2000 century match up with the 2001-2005 GS300 radio. Meaning something like a Grom vline2 could very well work! Obviously I’d like to get some schematics to see if they are all actually getting wired similarly, but I think it’s a step in the right direction for my future 2025 ownership goal. (Can’t buy a house right now but can buy a jdm limo!XD) pictured will be attached below with captions.

[GameHunter]

Rest of the images...

[pugwonk]

Just was able to message them actually!(thanks internet!) it was a 2006 model that I was viewing in the video apparently. Very interesting but their implementation while works, may have been less plug and play as they mentioned needed to modify the digitizer… not my preference.

I think doing something with the touch screen digitizer is unavoidable if you want to have a touch screen interface on AA. You either need to hijack the panel for your own purposes (some info here on Facebook) or disable it and put a different touch panel over the top of it. As far as I understand it, neither of these options is destructive but it would mean that removing the AA system entailed removing the head unit to plug the touch panel wire back in.

You can control Android Auto using a four way joystick-style controller with a button; if you did this then you could leave the existing touch screen alone. I'm not sure about Apple CarPlay but I'm guessing it works ok with something like that too.

Do you have a link to the video you mentioned? I'd like to see what they did to the digitizer.

[GameHunter]

I think doing something with the touch screen digitizer is unavoidable if you want to have a touch screen interface on AA. You either need to hijack the panel for your own purposes (some info here on Facebook) or disable it and put a different touch panel over the top of it. As far as I understand it, neither of these options is destructive but it would mean that removing the AA system entailed removing the head unit to plug the touch panel wire back in.

You can control Android Auto using a four way joystick-style controller with a button; if you did this then you could leave the existing touch screen alone. I'm not sure about Apple CarPlay but I'm guessing it works ok with something like that too.

Do you have a link to the video you mentioned? I'd like to see what they did to the digitizer.

The Grom vline 2 that works with the 2001 to 2003 LS 430 and GS, only need to plug into the factory harness and then pass the through cables go back into the nav. It doesn’t disable any of the factory screens for climate or anything else. Basically allows you to long press on the disk/CD button to get into the Grom system which is a full Android computer with wireless Apple CarPlay and android auto. The video is very short and shows an assembled dash. I have a Grom vline 2 in my 2016 GS. Only disables aux in my case but is full screen! Then I can switch back to or press other factory buttons to display the factory system.

(Sorry for blurry photo but is a good example of what it does on screen)

https://youtu.be/BpluczmdIi8?si=v3uVX2ikg_6BDWuf

[pugwonk]

That Grom thing looks rather neat - would be kind of amazing if it did actually work.

I think my next challenge is going to be working out how the car tells the video player to stop (e.g. when you press the "CD" button). I think I'm going to have to honour these signals as I've noticed that holding the 2.1v "video playing" line high makes the car so convinced that you're watching a videotape that switching the stereo off just makes it come on again.

I also want to sort out the poor audio quality - I'm hoping that this is all down to me using the wrong ground wires, so I'm going to do some experimenting...

[pugwonk]

Made some progress mounting the backup camera today. The only part I've really done is put the camera on the license plate frame and get the wire into the trunk - I did double check that I hadn't damaged the cable getting it into the car but so far I haven't made any effort to route the wire through the car.

This is partly because I still haven't found a +12V reverse signal, and I can't really route this cable until I work out whether that signal is coming from the front of the car or the back.

[ZEN]

I guest this wire give 12+ with illumination light mode
O3 connector (O/D switch) pin5 (green wire)
E4 pin5 green

// Is there any green wire in your VHS connector?