check trans light flashing

Transmission fluid had zero to do with transmission function. The Eaton is not a true automatic. Its just a regular manual transmission with electronic actuators to shift it and operate the clutch.

Without giving us a fault code, we don't have much to go off of unfortunately.

 

Have the shop scan codes, pay attention to any that may indicate a fluctuating alternator. Especially if it shows voltage spikes.

 

Sometimes cycling key switch 2 times fast off/on/off/on will show flash codes on gear selection display. Not sure on FL. 25 is no codes present.

I would suggest getting hooked up. Even with a fault code, in depth troubleshooting will most likely be needed.

 

With some of the newer engines with all that computer similation a computer glitch can sometimes create a warning signal I will sometimes switch off the isolation switch leave it off for a couple of minutes then switch it back on let everything reboot and see if the warning light is still on if its gone it was most likely a computer glitch if not then there is an issue with the engine I'd check all the fluids sometimes it could be something as simple as the temperature gauge wire coming lose I had a cracked fan belt which had tore off the temperature connection wire causing the alarm to go off a minor repair however caused some major alarms to go off.

 

Ultra shift plus? Which trans?

FC 21 = auto netral park brake switch.