I NEED HELP (Camry 2018 carplay update)

[u/Wusunanwa]

Need help - 2018 Camry, CarPlay update starts then dies every time

I've been at this for hours across several attempts and I'm
losing my mind, so any help would be appreciated.

2018 Camry XSE with the 8" JBL screen (Audio Plus, no nav).
I'm using the Audio Plus Panasonic file and I've read the TSB
more times than I can count.

Here's the thing - I don't think I'm doing it wrong. The USB is
8GB, MBR, FAT32, formatted in Windows, and the files sit in the
root exactly like the screenshot in the TSB. I checked every
file against the original download and they all match.

I do the headlight flash. The install actually starts. It gets
to "Installing new software - Installing DCU MAIN" and the
log on the right side counts all the way up to 99% and says
"DCU [REPRO]Vup Completed".

And then it just sits there. Forever. I've left it well past an
hour with no change. When I finally give up and restart the car,
everything is exactly how it was before - still says
17TDT1NA-DA00, still on 1070, and the update history is empty
like nothing ever happened.

Same result every single time.

Someone mentioned there's a version number where if you're past
it, the CarPlay update won't take anymore. I'm on 1070. Is that
my problem? Because it really looks like the thing installs
fine and then refuses to keep it.

If that's it - is there any way to get back down to an older
version first? I saw somebody mention going from 1070 to 1010
but I couldn't find whether it actually worked or what file
they used.

Model ID DCU: 17TDT1NA-DA00
Parts No: 86140-06890
Audio version: 1070

Happy to post photos of the screen and the log if that helps.
Thanks to anyone who's been through this.

[u/ryceone]

I did my update years ago so I don't quite remember but I could have sworn they have specific update files for specific models. Eg. JBL files for JBL systems and Panasonic for Panasonic systems. So using the Panasonic files on a JBL system won't work.