Problems with Isuzu Rodeo 2002 "Reduce Power"

Greetings Dear Friends, again I resort to your close answers.
"I have an Isuzu Rodeo 2002 and yesterday I made a 4 -hour trip, a yellow light that said Power was turned on, the car is almost neutralized and after a time of rest this light goes out and everything returns to normal, I want to know that it is happening to the car, my impression is that either the oil is damaged or the automatic transmission filter is obstructed. Thank you. Contribution