According to the Helms, the bus between the nav unit and the touch screen is GA-NET II. I've been googling a bunch for it, and haven't come up with anything too solid. I've taken some data captures with an osciloscope, and it isn't obvious how the protocol works. I plan on taking some more indepth data captures with a high speed data logger soon to see if it makes more sense when I have several different messages to compare.

If anyone has any info about it, I would really appreciate it.

Thanks,
Dave

 

what the heck are you talking about? im interested. teach me. and why are you talking about it. what are you planning?

 

I am planning on adding a computer to play mp3's and interface to an XM PCR sattalite radio. I would like to be able to control the computer from the navi touchscreen. So I need to be able to intercept the signals going between the display unit up front and the unit in the trunk. From what I've gathered from the service manual, the protocol that is used between the two units is called GA-NET II. I've been unable to find any information on it, other than a few CD changers for hondas that also speak the protocol.

I am going to take a closer look at the signals sometime tommorow. I'll post if I find out anything worthwhile.

Dave