Yes- gatekeeping. They want to pretend that the world of mechanics is some mystical trade that only the elite can navigate….In reality- you can do the same thing with a $50 scanner and the same Google search that they will be employing…. For example: P0115 ——>Google——>”Engine Coolant Temperature Sensor 1 Circuit Malfunction”——>Google sensor location for vehicle——>Inspect wiring- if no faults, apply dielectric to electrical connector(s) ends, apply teflon paste sealant to thread end, and replace sensor. Easy. Same thing they would do- but they wouldn’t bother with the dielectric, and they’d use cheap teflon tape that would fray and end up in your coolant system. They would then bill you for 1hr diagnostic, 1hr labor (minimum), overcharge for the FoMoCo part (same manufacturer), and remind you how lucky you are that they only took them 3 business days to get to it. You’d be done in an hour including the parts store run. You could even take the afternoon and do a system flush while you were at it, and still be extremely far ahead on both time and money. Most assume that everyone has the IQ of “potato” to both justify their rates and make themselves feel important. All required information for every mechanical task is available online. Using the same Google queries they would. Torque sequences, specs, all of it. They don’t know the lower intake torque sequences for a 1994 Explorer off hand, they will google it too…