Hi Jim,
There are two suspects of the failure: the oven temperature sensor and the control board.
The first thing I would check is the oven temperature sensor resistance at the control board.
Remove the sensor plug from the board and measure the resistance across the sensor wires. It suppose to be about 1100 Ohms at the room temperature.
If the reading is right then the control board has to be replaced.
If the reading is wrong then pull the range, remove the rear cover and measure the sensor resistance at the sensor plug (where it's coming through the wall). I would recommend to eliminate the sensor plug and hardwire it using a high temperature porcelain wire nuts to ensure proper connection.
If the reading is wrong then replace the sensor.
If the reading is right then check the wires and the plug connection at the control board.
- The part number for the oven temperature sensor is
AP204835
- The part number for the high temperature porcelain wire nuts is
AP3440522
- The part number for the control board is
AP3503544
Gene.