As the engine warms up the transmission does not shift into drive or reverse?

I have a basic OBD 2 scan tool. How is the scan tool in the link provided different? Also, will that scan tool you recommend be able to do all the things I need to diagnose? Lastly, I read a link describing how to fill the transmission fluid, but what is a good way to check the condition of the fluid? If there is dirt in the bottom of the pan that is being picked up into the filter, how am I to ascertain it’s there? I guess I can tell if the fluid looks burnt, is that enough?
Sorry for all the questions, thanks!

It’s a 3.6L, 4WD.

Could you recommend a CAN scanner, or at least what features, that at minimum it would need to scan for transmission issues? The article you provided only says that you can get them for as little as $35 on Amazon but then suggests I should look at what features it offers before choosing which to buy. Seeing as I look at this purchase as a potential one off, I don’t want to spend a fortune on a professional grade reader, when an inexpensive one would suffice.

I finally received the scanner you recommended. After updating the OS on it, I found no transmission codes and only one engine code, P1012, high fuel pressure. I’m going to assess the transmission fluid tomorrow. I had to get a T45 socket, mine came up missing. Will update you tomorrow.

I just goggled the code, p1012, all the results came back as high fuel pressure. I didn’t search it vehicle specific.

Here’s a sample.

I checked the fluid this AM. I didn’t do it precisely as the instructions said to, that was my error. Instead of getting the vehicle up to operating temperature before opening the drain plug, I opened it before I started the engine. I’d say about a pint or two of fluid promptly drained out. At any rate, I followed the rest of the directions perfectly. Vehicle to operating temperature, moved gear shifter through the range of selections, pausing on each one for a bit. I checked the level with a screwdriver. Fluid was just below the drain hole. No more fluid leaked out after initial opening, even after turning off the motor and during cool down. Transmission fluid looked normal. Red, slightly brownish, didn’t smell burnt and wasn’t foamy. My only questions are what’s next and is it normal to have that much fluid come pouring out, even when the engine was cold?

Like I said previously, nothing came out while running. Nothing came out after I turned it off for at least 15-20 minutes. I checked fluid level with a screwdriver both while running and 20 min after shutdown. The level didn’t appear to change. Both times it appeared to be full and level with the drain plug hole. The only time I lost fluid was when I first opened the drain plug, engine and transmission cold, I lost at least a pint maybe two. Vehicle was level the entire time.

Okay, what is the procedure for filling the transmission? Is there a spot to add transmission fluid or do you add at the same hole as you drain from?

Okay, I attempted to fill at the drain hole. I could not find a fill hole on my transmission. I warmed the vehicle to operating temperature. Opened the drain hole after going through the gear shift, stopping at each gear for at least three seconds. When I opened the drain, I got a steady drip of transmission fluid. Using a hand pump, I attempted to add more, but as much as I added, it just came right back out.
To recap, I have no codes after multiple cycles. Transmission is full of fluid up to the drain hole. Fluid is red to reddish brown and is not burnt smelling. I am no closer to diagnosis.
Do you have any other options?

It’s not that I’m not comfortable doing this, I don’t have the tools required. The scanner you advised I buy doesn’t have the capability to perform that test. The other tools I need cost a lot of money even if I go the cheapest route. They are also not available to rent at any parts store in town. I even tried to consult a bunch of mobile mechanics who could come out to perform that test and none of them could or will.
It would be cheaper to just replace the solenoid myself and see if that fixes the problem. At this point, it’s either that or just tow it to a transmission shop, which I’m trying to avoid.
Also, I never pulled the pan to check the filter. I assumed since the fluid didn’t look particularly dirty or smell burnt, it was unnecessary. What’s your opinion/advice?