I think I found a way to enable TV on Comand while in motion.

02-27-2003, 08:45 PM

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gareeb

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a car

Updated I think I found a way to enable TV on Comand while in motion.

This only pertains to those car models that don't have a true CAN-BUS.

You must be using the CAN-BUS Simulator from Megacomm in order to try it. The reason is that your VSS signal already coming across your CAN-BUS wires from the computer. You would have to hunt down all the speed inputs.

The CAN-BUS simulator takes the input for the VSS and illumination and converts it to whatever signals run across the CAN-LO and CAN-HI wires. Looking back at this post from when I was setting up my Comand for the first time made me ponder an idea.

CORRECTION!!!!
I am wrong in saying OEM CAN-BUS equipped cars are getting Navigation VSS from the CAN-BUS it is in fact getting it from a separate input on pin 6 of the C2 connector.
It is likely that there is another speed signal coming across the OEM CAN-BUS.

Quote:

John sent this to me....
....and it was helpful in verification:

Now the VSS wire. I used a black/green wire. Look at the picture I enclosed, I found 2 black/green wires that were soldered and covered with grey nylon sleeve. I simply removed the grey nylon sleeve and inserted a black wire( that goes to the PIN 6 on C2 plug), put back the grey nylon sleeve and use heat shrink tube to tighten up. I am not quite sure if the CLK use the same color coded wire. Here is the way I verify the right wire. The VSS wire has a (-) negative polarity. To test this, use a voltage meter( from Radio Shack), put (+) positive to PIN 4 socketA and (-) negative to the suspected VSS wire. Do this when the car is parked and not started. You should get a + 12 V reading. Next part is a little tricky; have everything the same but start your car and you will notice the reading is dropped to nearly 0. This reading will change if you start to move your car forward( DON'T TAKE OFF!) but wouldn't go to 12V. The black/green wire is from the rear axle and the green/white is from the front axle.

If I put a 2 way 3 pole switch with one side on a +12v constant. Which means the car is parked and engine off and make the other side essentially a pass through for the VSS into the CAN-BUS simulator. It seems like it should work at least in theory. Of course Navigation won't be as accurate but who navigates and watches TV at the same time.
With the flip of the switch then I can have the original VSS signal pass through.
I have been pondering this for a few days. Tonight I am going to try it.
I'll let you know what I find.

Thanks for listening

Well here goes

I finally got around to installing the Dietz Adaptor onto my European Comand 2.0 unit.
Well after wiring everything up to the switch for the VSS wire and +12V constant I took my car for a ride I hooked up my video camera as my mobile dvd player has not arrived from my ebay purchase yet.

I recorded some video of the unit displaying video as I'm driving. Then I drove it with the switch in the position to allow the VSS signal to pass through and what do you know the video still displayed.

I'm kinda stumped as to why it works, but I'm going to post the video and the configuration setup of my Comand unit. It kinda looks like I don't need the switch afterall.
My theory as to why it maybe working is that the OEM CAN-BUS equipped cars are getting multiple VSS signals accross the CAN-BUS. While those with the Megacomm CAN-BUS Simulator are only getting the one from Navigation. Or my TV Blocks were previously removed before I purchased it.
I will post the video tonight and the configuration when I get home..

CORRECTION!!!!
I am wrong in saying OEM CAN-BUS equipped cars are getting Navigation VSS from the CAN-BUS it is in fact getting it from a separate input on pin 6 of the C2 connector.
It is likely that there is another speed signal coming across the OEM CAN-BUS.

Last edited by gareeb; 03-14-2003 at 02:52 PM.

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