Coolant symbol came on although everything seems fine

Today after 25mns of driving and a 5mns stop at a shop the message came back within 2mns after I took the car back. Back at home I checked the radiator fan operation by pressing both "auto" buttons on the a/c for about 15sec and indeed the radiator fan speed increased quite a bit but that also triggered the message to be displayed. I turned off the engine then started it back and the message was gone but when I pressed the 'auto' buttons for 15sec that again triggered the message to be displayed as well as the fan speed to increase. So what seems to happen is that everytime the fan is instructed by the controler to go full speed it also triggers the message. Do you still think this is a controler issue or a fan issue? I am thinking that the fan either works or does not and it does work in my case. So that leaves the fan controler to be faulty or a bad wiring, right?

I am reviving this thread that I started several months ago. I never took the time to replace the fan controler that was possibly the cause of my Engine fan message displayed on the dash and whihc made me start this thread. Beside displaying the message when the car was hot and when the radiator fan was running at max the car never overheated and ran fine until now. Since yesterday though additional symptoms have appeared which I am wondering if they could be linked to the same cause that is to say a failing fan controler. For a couple days now the Engine fan message appears everytime the AC starts. As before the car never overheat and tmep stays always in between the 80 and 90 marks when hot. Today my step daughter was driving the car and she said she turned the AC on which triggered the Engine fan message on the dash and then the car stalled. She tried to start the car again the car would crank but would not start. She tried to start the car 10mns later and the car started and she was able to come back home. There is no error code in memory that my standard OBD2 reader can find. Beside the engine fan message coming on and the AC not blowing cold the car runs fine for now. One of my next move is going to be to replace the fan controler. I am not sure if the engine fan message issue and the car stalling today are related to the same fan controler problem or if they are 2 different issues. Of course the problem with the engine stopping when hot and not starting again after 10 mns make me think of the infamous cranshaft position sensor issue although it had already been replaced back 50kmiles and 5 years ago. I would think that a CPS issue would render an error code would it not? I appreciate idea or any though you folks may have about this.
Thanks

Here is an update. after my last post I checked the pressure of the AC and I was expecting it to be low since it only blew hot air. To my surprise the pressure was very high, close to 200psi! when the normal should be between 30 and 45psi. I have no idea how it got to that level. Anyway, I pushed on the AC valve to release the pressure until I got to the normal range. I then took the car which was already warm for a 20mns test drive. The AC worked wonderfully, it blew nice cold air and today the outside temp over here in Raleigh is close to 90F. The engine temp remained in between the 80 and 90 mark. The engine fan message never showed during my test drive while as I explained before it would show everytime the AC was turned on. So it looks like there is some kind of correlation between the engine fan message and the AC pressure. I checked the AC pressure after my test drive and it was OK.
The engine did not stall on me during the test drive although I turned it off and on several times, one time after 5mns waiting. Should the CPS not trigger and error code? Anyway I will drive the car all the week-end and see if the problems reoccur.