ok so i was wondering if u can use the toyota supra MKIV 5spd ecu for a SC300 auto to manual conversion. i know u can use the the ecu from the SC in which u received the transmission, the auto ecu, or the IS300 ecu, but i'm curious as how a 99 SC300 would react. would the check engine light turn on or will out run with no problems?

 

I believe no CEL will trigger if you use the auto ecu. The SC will behave like it should. You just have to bypass the neutral safety switch, or else you won't be able to even turn on your car.

 

I considered all the above but in the end I used what I had which was the 99 SC300 Auto ECU because the IS300 / SUPRA 5 Speed ECU you would need to have the Chip for your transponder reprogramed or get the chip with the ECU. For me this would have been a big time & money lost becuse I knew that an engine swap was in the my near future. With the auto to manual conversion the CEL would come with the AUTO ECU because of the ECU no longer communicates with the Transmission. DR.Tweak make a Transmission Simulator that should work with that auto to manual conversion.
https://www.clublexus.com/forums/per...peed-swap.html

 

Huh, Didn't know about the CEL.

Thanks for the correction

 

If you're doing an Auto to 5 Speed swap on a 99 SC you will have a check engine light that you can easily clear. The only way to avoid this problem is if you find the rare 96, 97 SC300 5Speed ECU.

 

I don't think that the 96,97 SC300 5 Speed ECU would work with the 98-00 SC300 because of the 2jzge vvti engine.