It’s always nice when a little DIY work can save you $30,000.
The 6 CD changer in the Prius wouldn’t play the other day. I noticed a CD partially ejected and when I couldn’t get the unit to eject it, pulled it out by hand. It has never played or loaded or ejected a CD since, showing errors including “seek error”. (The radio still works fine). A little googling revealed that a jammed changer seems to be a common failure in the Prius, and that having Toyota replace it might run $1000. The car has just about 100,000 miles, so I took it as a sign that it was about time for a new car.
I don’t know for sure what happened, but I suspect the “eject” 
button was hit accidentally, and the supports for the new GPS prevented the disc from ejecting fully. Thwarted by the failed eject, the mechanism damaged itself and got stuck in an unrecoverable position. But that’s just a guess.
I’ve long wanted a better aux input than the cassette tape spoof, but hadn’t found a cheap way to do it. Google showed that others suffering from the jammed changer syndrome elected to add a third party input adapter, usually including an iPod interface that was actually integrated into the car’s audio controls/display. I’ve never owned anything Apple, so that was uninteresting, but integration with the MultiFunction Display and steering wheel controls was very attractive. With no music in the car, the $100 price tag for an adapter suddenly seemed less of a show stopper.
I exchanged a couple of emails with GTA with questions about the unit. They were very prompt and provided completely helpful answers, so I would happily recommend them to anyone else considering such a purchase. I ordered a GTA Car Kits adapter ($115), a beat up 4GB iPod Nano ($22) and cable ($1.45!) from Ebay and a few days later had new toys in the mailbox. A youtube video from GTA showed how to tear the dash apart to get the old radio out. Doable, but a big production. Thankfully, they also provided a “shortcut” video that provided just enough access to get your hand in to plug in the cable by pulling only the glove box (trivial), the right center vent panel (no tools) and a wiring distribution block (one 10mm bolt). Given those choices, I decided not to even bother trying to (remove and!) fix the changer. The 3 CDs still in it will go with the dead car to the crusher.
The one 12 pin connector from the GTA adapter plugged into an open connector in the back of the changer (despite the fact that they sent a Y cable for those connectors). Apparently the nav system is connected similarly. I think the TX+/- are data for a CAN bus. That discovery led to a rabbit hole of reading about CAN bus info and hacks. There may be multiple such busses in the Prius, but an interesting one is accessible through the ODB-II connector. Hey – I bet I could get a $12 ODB-II USB or bluetooth adapter and look at all kinds of stuff going around the car network – maybe even the text of song titles from the iPod! And I’d been thinking about getting a cheap ODB-II tool just so I’d have it if I needed it for diagnostics. But in a rare moment of restraint, I listened to the little voice that said “Let it go, Jim!” I really don’t need more hardware to add yet another project to the list.
Back to the task at hand, I decided to mount the GTA unit to the wiring distribution block. Some inner tube rubber should keep it from slipping around. The connectors for the iPod cable and a 3.5mm aux input jack were still accessible by just dropping the glove box. Looks fine.
While the main glove box is always full of stuff, the top compartment is quite underused, and looked like a good location for the iPod. Some closed-cell foam made a reasonable grommet for the cable as it exits a 1/2″ hole drilled in the side of the compartment. Though not visible here, I did notch the corners to make it slightly more grommet-shaped and help it stay in place.
A gracious loan of a 30 pin Apple cable from Mike M let me start playing with the iPod a few days before the cable I ordered came. Putting music on the iPod was an ordeal, though mostly of my own making. In trying to use good old Winamp playlists with it, I formatted the flash, making it unusable with the GTA adapter. Due to a parallel project repairing a square dance recorder, at one point the iPod had a Rockbox firmware directory on it. Oops. ITunes was unable to “restore” the iPod firmware despite several attempts. Fortunately by installing iTunes on another computer I was able to get the iPod “restored” so it would once again work with the GTA adapter. Of course that meant that I’d have to use iTunes to put music on it.
While I eventually made peace with iTunes, I swore at it a lot in the beginning. I tried to create a login, but when it required a credit card, I gave up. It said I could just drag and drop .m3u playlists in, but they came in empty. I got some malware while installing a tool to convert .m3u playlists to Apple (that didn’t even work). I eventually found a forum post saying .m3u playlists would work, but only if they had full paths. After globally prepending “I:” to the file pointers beginning with just “\mp3\playlists…” the playlists imported to iTunes OK – and brought all the associated music files with them! There was a bunch of time spent deciding on and cutting down playlists to limit the music to about 45 hours to fit the 4GB flash, but that wasn’t iTunes’ fault. I’m still not comfortable with iTunes, but it got the job done.
With the iPod plugged in, sure enough it showed up as CD Changer 2! Of course the original non-functional one still showed up (as CD1), but I could skip over it with the steering wheel Mode button (but only that way!). Disc 1 shows up as “Hybrid”, and might play the audio from either iPod or 3.5mm jack (or both?), but discs 2-6 are Playlist 1 – 5. The 6th playlist shows up in some places as “Disc 7”, but there’s no extension of the Disc 1-6 display. While I’d told the iPod to “Shuffle 1 Playlist”, each playlist seems to play in order unless I touch the Disc Rand button. Not a big deal. And when I touch Title, another screen shows the actual track title! I never found a way to name the playlists, though.
Here’s the iPod in its final bubble-wrapped home. It’s completely functional, sounds great, and is exactly the hands-off installation I’d hoped for. And now that I have music again, it saved me from having to buy a new car!