I put a 98 (auto) engine in a 97 (manual) car. I'm bringing the entire wiring harness and ECU with the engine. I plan to connect everything this week. I don't have the wiring harness or ECU from the 97. It was a roller when I bought it.

I'm assuming I'll have some ECU issues. If nothing else, the ECU won't see the original transmission. I'm also thinking it won't have a neutral safety. Maybe the speedometer won't work?

I'm hoping it will just throw codes for these (and whatever else comes up), but otherwise will work, and I can sort out the codes once it's running. The engine ran perfectly before we pulled it (about 100k miles).

Does anyone know if the car will run/operate with the ECU/transmission combination? Is there a way to program the ECU for the new transmission? Should/could I swap in a new ECU?

 

As far as I know, you will need a manual ECU if your ‘98 engine is connected to the existing drive train.

Ask Craig, but he is going aftermarket ECU but the wiring harness issues compound the approach.

 

I found an old thread (below) on this with some good info. It looks like I'll have codes and the CEL will be on, but it will run, which is fine for now. I do have the original automatic trans, so I may look into pulling the sensors out of it to make it think the trans is still hooked up, like they talk about in one of the linked threads.

The only other option without going aftermarket seems to be to find a 97-only manual ECU. I need the ECU to include VVTi, OBDII, and manual. I'm gonna guess that will be like finding a needle in a haystack, since only 120 or so were even made. If anyone happens to know where I can find one, let me know. Otherwise, I'll stick with the existing 98 ECU and address the codes.

https://www.clublexus.com/forums/sc-...cu-needed.html