F150 2008 FX4

Hello! I had rusty and leaky transmission cooler lines for weeks. I had to top off the fluid every few days to avoid slipping. Finally I took a couple of days to pull the lines out, and also changed the small aux trans cooler. It was pretty straight forward, I did have to get a new valve (the blocky thing at the lines near the transmission (Valve 7L3Z-7H322-A). I paid attention to put it the same way the old one was.

So tighten everything, pushed in all the quick disconnect into place, started the engine, no leaks anywhere yay.
I added about 2 quarts of fluid and checked the dipstick. It's near where it should be, a little bit on the low side.

But now, the gears don't engage at all. No reverse, no drive.
What is happening? Could it be a PCM issue? Currently I disconnected the battery and let it cool for 20 minutes to do the rest procedure. Any ideas? Thanks!

Edit: I did have a code: P0191 : (FRP) Sensor range/Performance

 

Check and double check all wiring harnesses you might've disturbed.

 

Wiring can't cause this. Not enough trans fluid will cause this.

 

Fluid should be checked in this fashion:

Start the truck and let it warm up. Move the shift lever through all positions, pausing 10 seconds in each position. Put it in Park and check the fluid with the engine running.

 

Yeah I checked any wire that was in the way, it seemed OK.
I added another quart and it seems like it wants to move now. I'm nervous so I didn't take it more that 20 feet out, I'm gonna buy more fluid today.
Looks like I underestimated how much fluid I needed to add after changing the cooler. It's always a bit tricky for me to check the fluid because it "looks" like the dipstick is wet but not all the way to the edges. Meaning that it probably just shows the residues of the fill tube.

Hopefully all will be good after I add more. I'm glad nothing is broken!

 

Great to hear!

Looks like Mark still knows his stuff.