1990 E40D
You actually don't need a fancy device to see if your pcm is commanding the shift or not. I think it is of course, because it's doing so; just late. Why late, and why only when warm? Here's the list of a no 1-2 shift.
How to test solenoids:
Here is the 1-2 shift valve location, if you want to pull it and inspect it for sticking.
Here is a cheap/free way to see if your pcm is commanding the shift, or for you to force it manually:
That is if manicmechanic, doesn't volunteer to mail you his nice fancy tool

Feed bolts:
(You have to drop the valve bodies. Don't lose check *****!)
Good luck!
Last edited by FORDF250HDXLT; Apr 19, 2026 at 11:52 AM.
You would be surprised how many transmissions get overhauled due to an engine miss
That code 49 means spout grounded which sometimes boils down to a faulty TFI or stator
That will cause a miss enough to affect the trans
Get the pinpoint tests out of the 1990 PCED or off AllData for code 49, and do them
I worked on a BMW and #4 cylinder was weak. I do not have the tools to check the compression/CLT so I referred the client to a shop I know. After $3,000, they told him that #4 cylinder is weak and needs headgaskets [$15k]. Part of that $3k was to install 2 new front O2 sensors because the 'Engine ran better with them unplugged'.
The car came back to me, I made an adapter so I can check the CLT,. #4 has 95% leakage. Leaking past the exhaust valves. How can the engine run better with 2 O2 sensors are unplugged with a dead #4 cylinder? So, rebuilding a transmission for a misfire sounds normal. Forcing the client to pay for a repair that did not fix the customers complaint is also sounds like standard business practices.
I charged the my client nothing.
There are more professionals that are terrible than good ones.













