I own a 2020 f150 with 2.7 engine. At 26,000 miles. The truck has been sitting for two days. When starting the cold engine I got a coolent overheat warning message with the check engine light. Several attempts at different times and days continued the false overtemp warning. I am told by a local shop that this is simply an overtemp sensor. I attempted to take it to the Ford dealer for the repair, but found them four months behind for "heavy maintenance". A local Midas shop said it takes two days to replace the sensor.
My question is really a reliability question.....Can I expect this as a common and frequent problem?

 

This can possibly be a simple issue. With minimal cost and effort, R&R your cylinder head temp (CHT) sensor. Can get from local parts store or maybe Rock-auto online. The sensor on the 2.7 L is easily reached (right next to oil dip stick). Unplug electrical connector (my 2.7, 2015 was YE-GN & BU-GY wires), remove old sensor (no coolant because it is just pressed up to the cylinder head), put in new sensor, and plug in electrical connector. NOTE. install only ONCE to the proper torque!, Not a reusable sensor. DO NOT TORQUE TWICE! ONLY ONCE! I'm NOT a believer in the "PARTS CANNON", but this is an EASY and CHEAP attempt to resolve your issue.

ADD- If it turned on the MIL light then the workshop manuel notes.......NOTE: The MIL can only be extinguished by using a scan tool after the fault has been rectified and the DTC cleared.

 

2015, 2.7L engine

 

Any vehicle can have a sensor go bad occasionally. In my experience with a couple F150s, it's not frequent. My last truck had the oil pressure sensor go bad after about 6 years. My current truck had a BLIS sensor that went bad the first week I owned it, and replaced under warranty.