1G Yellow Hot Auto Transmission solenoid

[EndoT]

Good morning, I am trying to diagnose a transmission issue with my sons 1994 Mitsubishi Eclipse NON-turbo automatic 2.0. When we first got it, it wouldn’t move at all. After unplugging the solenoid plug below the battery, it came into limp mode third gear. Car has under 100,000 miles. I tried to obtain codes from TCU to no avail and suspected ignorantly that the TCU was bad, purchased used “good” TCU installed started up put into gear drove about a mile and shifts were erratic.

I’m feeling only first and second and then nothing no forward or reverse. Brought it back to the shop, followed John’s article on testing solenoid wires, the yellow wire is for some reason hot all the time. As soon as you start it, the yellow wire is hot in every gear, low, second, drive, neutral, reverse, park. Yellow is hot.

I have scoured this site and found nothing to inform me on why the yellow wire would be hot all the time.

 

[EndoT]

OK, here’s an update.

I read somewhere that there are transmissions in these with three sensor locations. When we got this 1994 Eclipse I noticed right away that up into the right of the dipstick tube there was what looked like white silicone. Sure enough in one of the pictures of a member here he showed that as one area where the sensor goes. I have one sensor on the rear and one on the bottom left, I’m wondering if this is my problem, why my yellow wire is hot all the time. I’m supposed to do that conversion where I wire in all three plugs like maybe someone replace this transmission out of an older model and put it into this 94?

This is the code of my transmission 4FA222MPF6

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