Ok today I did some more tests with the NAV unit.
First of all for all of you who are experiencing the firmware lost issue I know what is the problem will cost you $2 to fix. In the left side of the DVD module is a CR2032 Lithium battery. That battery is suppose to hold your firmware in memory for 1 year when new. In time does not hold the charge so you end up loosing the firmware if the car sits for a while. So go to your computer/electronics store and ask for a CB2032 battery. Take the HU out of the dash and remove the top cover, then the DVD module (held in place by 7 or so screws). Replace the battery (require soldering) and you are all set.
Now back to my navigation issue.
So now I have BOSE thus no excuse should work. Well I connected the unit to the car data link connector (all you need to connect is power and one of the data wires). First strange thing was after loading the firmware it did not beeped (strange).
With the firmware loaded (same 3.10 version) it does follow the dimmer switch (I turn the parking lights on the back lights on the NAV unit turn on, I am turning the dimmer switch the light do dim accordingly). There is a ~0.5s delay witch is due to the time it takes for the NAV unit to receive the information from the data bus.
Then a little bit more hope, if I turn the radio on (remember I do have a BOSE in-dash HU) well the sound is pulsing (between the HU volume and a higher volume) with a frequency of 1-2 pulses per second. So basically there is a “fight” for the RIM control between the in-dash CD BOSE HU and the NAV unit.
If I press the music button on the NAV unit the sound gradually mutes in 2 seconds or so. The same happens if I press the NAV button and TILT. Turning the volume knob on the BOSE HU the sound is back (with the same pulsing volume effect). Unplugging the NAV unit the sound is instantly back to normal.
The only difference with the unit connected to the data bus and unit disconnected is that w/o data bus connection pressing SETUP button (for 4-5 seconds) the unit beeps once, while if connected to the data bus it doesn’t. Also w/o data link the unit shuts down after ~15 seconds while w/data link it stays on.
But regardless it does not responds to any button and NO image at all.
Agrrrr

, if I only had a way to convert the CAN protocol on the car’s network to a RS232 signal so I can see what’s going on with that data bus!
I still believe there is some message that the unit expects to receive from the car’s network and it doesn’t. So far I suspect the problem is with the VCM module witch is missing in the ‘96-’97 Seville and ‘96-’02 Eldorado, but is present in the ’98 and up Seville (and Deville at some point after).
Anybody knows where is the VCM located in a ’98 and up Seville, or has a picture with one. I am looking for one to have-it connected to the data bus along with the NAV unit, maybe that’s what the NAV units is looking for.
Can anybody help me with a GEN I firmware?
And the only code I get is:
B2462 - GPS Signal Error
If I disconnect the GPS antenna, other than that NOTHING.