I have a 2001 5.4 lariat. Shifts points are perfect for all gears. However, when I am exiting an off ramp at 60 I have to rely only my brakes to stop. Trans stays in 4th until I get down to 5 mph until it goes into 1st.

Going up a mountain trans will downshift into lower gear fine. Going down the hill I am in 4th all the way down. Even after tapping the brakes. Have to manually downshift if theres a light at the bottom.

Autozone showed no codes.

 

There are no codes because there's nothing wrong that the PCM can detect.

 

How long have you owned the truck? Has it always done this? Automatics by design don't feel like they are downshifting (unless you have one with a tow/haul mode) until you are at a near-stop (2 to 1) but they are.

 

May not be revelant but I had a problem with a C4 3 speed auto not downshifting and a fluid change fixed it, twice over the 10 years I owned that car.

 

Your transmission is electric controlled by the computer for upshifts and down shifts as dictated by sensor input data from several sources.
This total system is monitored by computer diagnostics.
If there is an issue with shifting, the monitors see it.
Your OD does not upshift until about 45 mph and will fall out of OD at about the same point in road speed as you decelerate with no throttle applied.
So far you have not indicated a real issue except from expectation.
If OD were truly in at such a low speed it would be detected with a code telling you the TCC is stuck..
If however there is mechanical internal issue such as the converter diode lockup malfunction, that could result in a converter mechanical lockup.
This type is not an electrical issue so the computer cannot detect it.
Better be sure you have a problem.
Good luck.

.

 

An auto tranny isn't going to slow you down when you let off the gas.

 

Let it die. The guy registered, posted, and hasn't bothered even coming back to check.