Gone_Rabid

Purchased an 88 TCU. I will update once it’s delivered and installed.

thanks for everyone’s help.

cruiser54

I was under the impression that the 91 and later TCUs WOULD plug in where an earlier one goes.
I may have one of each I could look at.

lawsoncl

The plugs are identical except the small ridges on the top are in a different spot. Easy enough to trim them off or use brute force to plug different colors together.

cruiser54

LOL. I'm thinking there has been some brute force **** happening!!

Gone_Rabid

Installed the correct TCU this morning and took it for a spin. Transmission is shifting properly, shifts at ~5k at WOT and it kicks down like it should.

thanks for everyone’s help. It’s much appreciated.

lawsoncl

Bingo! I love it when the fix turns out to be that simple. I'll have to add this to my very short list of when the TCU was actually the problem.

You can probably sell the old one on eBay for a pretty penny. The last one I sold a few years ago went to a guy in the UK for $60, who was trying to retrofit the AW4 behind a diesel and was thrilled that I had the wiring harness to go with it.