Rad fan on always ofter engine shut off. no hot engine message temperture guage at normal range fan stays on @2-3min after engine turned of regardless of running 1 min or 1 hr.

Did you change thermostat?

the guage is not too accuate, we use tools to measure real heat.
but if it slams to max. that is bad, (if the sender even works)
if really hot, truly , acutally
that means the auto RAD fan is(are) failing.
the test is easy, you drive 20 miles, park and idle until the RAD fan
come on, if it dont it is bad. (fan , wires, sender or controllers)
easy huh?
and if bad, you then ask, how to DIAGNOSE it. (no guessing)
buy a DMM meter, and its easy.

You NEED to go back to that shop and tell them to make it right-or call the state attorney generals office if they wont. They should never have told you to leave with a idiot light on after doing the work on your car!

Is the air dam at the bottom of the front of your car intact? If not it will definitely cause the engine to run hot at highway speeds since not enough cooling air will be passing through the radiator.

It could be the impellor wearing out on the water pump, though I have not heard of this issue in your make of car, I have seen it first hand in other makes. The thermostat may not be opening up all the way, flow restriction,. The coolant temperture sensor could be going out, and the gauge in the dash could be going out. You could have flow restrictions else where in the engine. Have you ever had the engine flushed? these are the things that I can think of that would make your engine run hotter than normal.

The car has a computer that is linked to the engine. It is hard wired to it meaning the computer is always on. Upon shutting your engine off taking the keys in hand the computer is still on sensing the engines temperture. The coolant sensor will send power to the relay to keep the fans running untill cooled down enough. Then the sensor will cut off power to the relay shutting off the fans

Remove the return pipe to the expantion tank.Thats the small pipe.Hold it facing down with engine runing untill you have a costant flow of water.If the fan stays on then you need to replace the fan switch.

Replace the cooling fan sensor.

With engine cold, remove rad cap & check level in rad. Top it up if needed to 1 or 2 inches from top. Start engine, turn heater on (not defrost) and observe coolant level as engine warms up, add if necessary. Radiator fan should be off, and only come on when engine reaches normal operating temperature, for a short time, then shut off again. Let it run until that happens about 3 times, then put rad cap back on. If temperature gauge climbs up over normal toward hot, too much, shut it off. Do you now have heat? Is rad fan acting as I described? Let me know.

You need to check coolant level in rad, when cooled down, and top up your return bottle to marked level.
Start by having coolant (antifreeze) ready, remove your rad cap, and top up the rad level, then start the vehicle, and turn on your heater (not defrost) . Let it run with cap off for a while, and keep an eye on level of the rad & top up as necessary, but leave an inch or so from top.Let it run & observe your guage while doing so, and when gauge gets to normal operating temperature, your rad fan should come on, run for a while then shut off for a while, then back on again after little while, and off again. Let it do this about 3 times, top off the rad as described above, put cap back on tight, and top up your coolant return bottle to mark on side. If your rad fan doesn't come on around normal operating temperature, and gauge heads too much towards hot reading, shut vehicle off, that's an indication that your rad fan fuse has blown, or relay, or fan itself is defective. If all works well & you now have heat, great, but keep an eye on your coolant return bottle level for next while to see if it keeps going down, and add as needed if it is. If the level in bottle continues to go down, you've got a leak in the system somewhere & need to address it a.s.a. p. to hopefully avoid bigger problems, but we'll get to that only if we need to. Do what's up above and let us know the results.