I have started on my conversion and just to fool around I pluged in my manual ECU in place of the Automatic ECU.

The car cranked up, I took it for a cruise down the road and even turned the cruise control on at 70mph on the highway. I was under the impression that the manual ECU wouldn't even work in the automatic car period until some rewiring was done or the whole in dash harness and guage cluster was replaced with its manual counter part?

Now my question is when I put in the manual engine wiring harness will this all change? Keep in mind that right now I can do everything with the manual ECU I can with my automatic ECU except for the "Hold" feature as expected.

Since all this works right right now, when I install my manual engine harness will this throw all the other components into caos and I will have to rewire or can I still keep the auto chassis harness with the manual engine harness and it all be functioning as it does with the manual ECU in the Full Auto setup just that the "hold button" doesn't work?

 

You'll find that the harness plugs are TOTALLY different everywhere except the 4 for the ecu itself, so that throws your idea out the window of just swapping the engine harness. To change the engine harness, you also have to either hack/repin lots of other wires or change the harnesses to match.

As for the ecu differences, I suspect it's minor stuff like timing curves etc. THe actual auto trans ecu controls the trans function, and as long as it's there and plugged in then the auto trans stuff should stay pretty happy.

 

I thought I had a good thing going on here too. Thanks for letting me down lightly and for that tad bit of info that I was unaware of. Back to the drawing board to figure this whole electronic mess out with some good older info on here.