Are the Manual and Auto ECUs interchangable?

[BosnianLanos]

As some of you may know, I had a problem with the VGIS being permanently on in my new manual Lanos. Well, I was advised to swap the ECUs in my automatic Lanos and manual Lanos to see if that is the problem. Well, last night, I did just that. I'm pleased to say that it really is the ECU that is causing the fault with the VGIS system, and the automatic ECU makes the manual car run great, better than the manual ECU ever did. Also, it has been said that a automatic ECU will work flawlessly with a manual car, but not the other way around. Well here are the factoids I have found regarding this information.

Manual to Automatic Computer Swap:
Contrary to popular belief, the manual computer did work in the automatic car. But work well? No. To begin with, (as predicted), the transmission didn't function well, but it worked. When put into reverse, the tranny would slap into gear really hard, and when put into D4, it would smack really hard again. The PWR button was permanently on and could not be shut off, and the car would not cycle into the higher gears. To top it all off, the speedometer didn't work.

Automatic to Manual Computer Swap:
As was predicted, the automatic computer worked relatively well in the manual car. The only problem was that upon startup, the RPM would spike to above 2000 RPM, stay there for a few seconds longer than usual, and then go down to normal idle. The CEL came on instantly and stayed on, and every time you'd get to a higher RPM, it would start blinking (Almost like a shift light, LOL). However, the VGIS worked flawlessly and as mentioned before, the car ran perfectly. And, similar to the other swap, the speedometer didn't work.

Bottom Line:
It seems that the automatic and manual cars get their speedo signal from different sources that are not interchangeable. Also, the automatic tranny throws a CEL because I guess it can't register that there is a transmission attached to the car. The manual ECU makes the auto run like hell and is really not recommended. So, in conclusion, if you feel that you need to swap out your computers, I suggest that you get a computer from the same transmission car so you don't run into any of these problems.

[MMamdouh]

very valuable feedback... thanks for sharing.

MMamdouh

[daewoomofo]

thats good to know for if some one is gonna do a auto to manual swap! (me.....one day, far a way)

[chronoti]

OOOOOOOOOOOOOOR, if you get a ecu pin out you can find where the speedo wires differ, and for the auto tranny missing on the manual, you can trick the ecu buy putting a LARGE resistor that will throw the wires for the solinods to ground.

[Daniel]

That's good to know.
Do you plan to repair your ECU?

Daniel

[woo]

for the manual on the auto computer there are ways into tricking the computer into thinking it has a trans hooked up. The auto would be behaving badly on the manual computer because it is probably electronically controlled. My leganza has a hydrolic controlled auto so it doesnt need a computer, just like the th700 that was put into my brothers car. Old technology can be good at times i guess

[BosnianLanos]

UPDATE:

Today after driving the manual Lanos for a while, it seemed to be working ok, but after about 30 minutes of driving, it started to stall out on me. Everytime I'd put it into neutral, or even depress the clutch, the cars RPM would dip to below 500 RPM and then stall. I swapped the ECU's back to where they should be and both cars are working fine again. I guess I'll just go to the dealership to get my ECU flashed with new program or something that'll make the VGIS work again.

So, truly bottom line. OPPOSITES DON'T ATTRACT! Always get the same ECU that came with your car!