It looks like justchat_1 was right, and my friend from IPD was wrong. This is out of the offical Volvo advanced diagnostics information system, specific info for my car:
Since the language can be changed entirely via one module update, the text messages must be stored in that module.Originally Posted by VADIS2004C
Oh well. Someday, when I have apsolutly nothing better to do, I may go to a junkyard and pick out a DIM to take apart and try to reverse-engineer the EEPROM. Till then
Follow me on twitter @Danny117
@theshadow27: I wouldn't dismiss it too quickly. The Saab has a similar LCD display and while some of the messages are reactions to specific CAN messages (and in specific languages), it can display two lines of user-generated text (with the right hardware/software of course).
Look at Tomi Liljemark's website (http://pikkupossu.1g.fi/tomi/projects/i-bus/i-bus.html) on reverse enginerring the Saab's CAN bus protocol. It's because of his work that I've been able to send text messages to my SID using Microchip chips. A friend of mine and I are in the early stages of decoding the CAN messages for the message center in his Dodge Charger.
Grabbing a DIM and listening to the bus will get you there. But as Dejan said, it is going to be manufacturer (and possibly even vehicle) specific.
@Saab9-5 - Thanks, I haven't completely given up. I found a DIM on eBay for $30, and while it won't work in my car, I'll try to get it running on the bench. Maybe suck out the flash on the controller... Lots of possibilities. I'll know more when it gets here.
@andycjx - I have a copy of VADIS which is an older version of VIDA. The actual DiCE module is around $1500, and won't share any of the proprietary CAN information with it's user. It would help the process along much faster though, unfortunately it's out of the budget.
@DANNYDOTNET - I was thinking about a HUD, and spent a few hours searching around. It doesn't look too hard to pull off. My fundamental problem with a HUD is that it projects an image on the windshield... Of all the things you don't want projected on your windshield in VA it's a radar detector's output!
FYI I got this somewhat working on my Mazda3. Displaying text of my Radio LCD is technically possible and actually quite easy to do. Problem is that there is no plug and play solution. You have to physically place some electronics in-between the wires going to the lcd. I tested this theory but with just tapping the wires and my text was displayed on the lcd, but soon enough the radio text overwrote my text. I had to keep sending my text every 100ms or so but eventually the car noticed it was receiving way to many text commands and decided to ignore them all. This is why you would have to sit in the middle of the commands.
I may look into doing this correctly just for fun, but I personally have no practical use for it. Also the fact that it would be only for a Mazda3 and not easily upgradable to other cars (as the code would be on a microchip). If I made some PC software to do the work and not so much code with the microchip this would be doable and should be upgradable to all cars as the PC software would setup to know what commands are for the Mazda3 versus other cars.
V1Connect - Valentine1 Serial Adapter http://www.v1connect.com