Engine cooling fan always on high

I have the ecoboost 1.0l engine. The engine cooling fan will turn on high five seconds after starting the engine and remain on. Its winter, so the AC's not on and the engine is starting cold. There is no check engine light, and the coolant temperature gauge is working normally (ie it starts at zero and gradually ramps up to the midway point as the engine warms up). Using an OBD scanner and FORSCAN, I can see that the cylinder head temperature sensor is "stuck" at 215 degrees F. Even when the engine is cold, it is reading 215 degrees, and does not vary as the engine warms up.

This could indicate a bad sensor, and the fan is running because it thinks the engine is hot. Unfortunately, this sensor (part # D2BZ-6G004-A) is on nation-wide backorder with no ETA. It does seem rather strange to me that a bad sensor would give a "stuck" reading like this, considering that it is an analog thermistor, it seems like there would be some fluctuation in temperature reading even with a bad sensor.

Could this be caused by another problem? I checked the fuses and they are fine. I would like to check the connections on the CHT sensor, and take an ohms reading, but I cannot find the darn thing. I think it might be pretty buried in this engine. Also, I have noticed a big drop in fuel efficiency since this fan thing started happening. Would the engine use more fuel if it thought it was hot? Is it okay to continue to drive the car while I wait for Ford to figure out how to manufacture this part, or am I putting a lot of wear and tear on my drive train?