can you hook your ecu to an aftermarket nav system to display every parameter that a PC can?

 

I don't have any ECU reader experence but if they require a PC to read them it is possible. What you'd have to do is to connect the PC to the ECU and take the normal VGA computer video output and run it into a converter to change it to composite video. That composite video signal is what the dash displays - DVD's and navigation units are creating. The output video of the computer will need to be matched to the input of the monitor - try starting with 640 x 480 resolution. Many monitors and converters will do better than that but that's a safe place to start.

 

I think he was asking if he can hook up the ECU directly to the dvd/nav instead of actually having to use a PC. No idea. I know a good bit about car audio, but I've never seen it done. What parameters are you trying to read out? A/F Ratio and stuff like that?