Hey Guys,
trying to help out my nephew since im an old OG Club Lexus member. I searched a few threads but didnt find anything concrete. Here is the situation:

2000 GS300 NA-T (GS300 engine 550cc, 70mm turbo, stock GS300 harness and stock GS300 tranny)
We want to run an Aristo ECU to make the stock fuel map closer to a boost friendly factory tune. (we can clean the tune with a Emanage piggy back later)
We plugged in a working non-immobilized ECU. Car runs and drives, but it does not shift. Is there a speed sensor wire or something that needs to be repinned from the Stock GS300 harness to the Aristo ECU?
I haven't troubleshot this stuff in over 10yrs Im hoping someone here is versed in this aristo stuff and may have run across this problem. Any suggestions would be great. Im providing remote support, so I'll have him pull the CEL codes and verify if his speedo is working.

Thanks in Advance
BDR

 

I've not waded into those waters myself, but I've heard that the A650E stock trans will not properly operate with the Aristo ECU, and likewise the A340E trans will not effectively be operated with the GS300 ECU. If I were in your shoes I'd stick with the stock ECU as long as you're sticking with that transmission. Not sure to what lengths you'll have to go to manage the fuel & tuning with forced induction, but I believe it can be done, even if it means you have to go to a piggy-backed ECU such as an AEM, Haltech, etc.