Last year our frig wouldn't keep everything as cool as it had been. I attributed that to "excess open door problems". Cooling was very good sometime and just marginal at other times.
On a 3 week trip out west the frig started failing with a "no cooling" error code. After being reset it might work for a few hours or a couple of days. Cooling was marginal when working. Threw the food away twice.
To make this a shorter story, the vent fan had failed. What we learned was the frig worked OK when moving down the road. When we stopped moving and the temps were hot it failed with the error. When in the mountains where there were cooler temps we had no error codes but it didn't always get as cold as it should.
The freezer, except when the unit had fail with the "no co" error, was still getting cold enough to make ice, although we think it took longer.
I replace the fan and added an extra "helper/auxiliary" fan just for backup.