I'm trying to sell my 88 E350 and the heater core took a **** on the ECU. I've put a new motor in this truck out of a 91 E250. I saved the computer from the donor truck. Will the E250 computer work besides throwing codes because it doesn't see the trans? The wiring harness was different on the 91 but the ECU pin out is the same.

I'll never get what I have in to the E350 out of it so I just want a cheap way to get it running. I'll tell the buyer what I did and why its throwing codes.

The 88 has a 351w w/c6 F8TF-12A650-AU1B
The 91 had a 351w w/e4od F2TF-12A650-LA

 

I do believe to pull the E4OD out and swap in a C6, or install an engine that had the E4OD, you need the manual trans ECU for that same engine so it is not looking for the E4OD signals.

 

Yes, it should work, except it will turn on some lights and set some codes.