SYMPTOMS
What happens is if there is a short internally on the temperature sensor from the +3.5v to ground, this will cause the Controller's power supply to be pulled down, which inturn will reboot the controller. If left in this condition, it would more then likely cause the Controller to stop working all together after a little while. This is a hardware failure.

If the temperature sensor was not shorted and functioning correctly, just sending a temperature reading that is out of range, this would cause a temperature error on the Controller.

RESOLUTION
To check the temperature sensor with an ohm meter do the following:

Set your meter to read ohms.

With the temperature sensor disconnected from the Controller measure pin 1 (red) to pin 3 (black) on the sensor plug itself. The value the meter reads should be a very high value = > 10,000 ohms.

With the temperature sensor disconnected from the Controller measure pin 2 (white) to pin 3 (black) on the sensor plug itself.
The value the meter reads should be a very high value = > 10,000 ohms.

In the same manner check pin 1 (red) to the brass sensor cover, then pin 2 (white) to the brass sensor cover, then pin 3 (black) to the brass sensor cover.

None of these measurements should be below 10,000 ohms.