Here are your parts
Parts for Frigidaire PLES389ECB Range - AppliancePartsPros.com

Please see the attachment for the wiring diagram.

You will see two thermal breakers in the probe circuit perhaps one of these is blown.
The parts diagram shows three of theses but I am not sure which is which so you will have to trace the wires.
They are items 119 and 219 in section 05.

One of them looks like it has a button on the back of it that will pop out if blown. It can be pushed in to reset it.

Unplug the unit and then check them with a meter.
If OK then check the probe circuit at the board.
P5-5 to P5-6 I am vot sure why the diagram shows doubling up on the numbers but both wires to the probe itself should be violet.
It should be about 1100 ohms at room temperature.

If a thermal circuit breaker is open either replace or reset it.
Then check what the actual oven temperature in the oven is using an oven thermometer just to be sure that it is not running hot.
most ocens can be calibred plus or minus 35 degrees.