If the oven isn't heating to the baking temperature you set — it's too hot or not hot enough — the oven temperature sensor could be malfunctioning. Or the problem could be with the electronic oven control board, which controls oven functions.
You can test the oven temperature sensor probe by unplugging the range and measuring sensor probe resistance using a multimeter. It should measure about 1,080 ohms of resistance through most probes at room temperature.
Refer to the tech sheet for the probe's resistance specification for your range. You can likely find the tech sheet in the control console or taped to the back of the range. Replace the oven temperature sensor probe if the multimeter doesn't measure the correct resistance through the probe. If the probe is okay, you might need to replace the electronic oven control board.
Here are other likely causes:
If your oven uses a control thermostat instead of an electronic control board to control oven temperature, the oven control thermostat may have failed.
In a gas range, a weak oven igniter may intermittently fail to ignite the oven burner, preventing the oven from reaching the set temperature.
If food isn't browning, the broiler element or burner might be at fault; many ovens activate broiling briefly to brown the top of baked dishes.
The oven won't bake properly if the oven door doesn't shut fully. A problem with the door hinges can prevent the oven door from shutting properly. Adjust the oven door hinges or replace them if damaged.