I replaced my stock mirrors on my 2020 with tow mirrors after I put them on the check engine light came on and my air stopped working I had the code checked and it said it was not reading the sensor I don’t have the new mirrors plugged in yet because I have to get adapter harness for 8pin to 22 pin connector which will be tomorrow when I plug them in will the sensor start working I replaced my stock mirrors with mirrors off a 23 250 is the sensor in the bottom of the passenger mirror I don’t understand why my air conditioning stopped working because I had them off and unplugged when I drove to change them and my air conditioning was working fine

 

May be it took a power cycle for the computer to realize the temp sensor was no longer available.

 

It takes a rest period during which the PCM checks several different temperature sensors. The following is from the Workshop Manual:


Compressor control and the evaporator temperature are a function of many parameters, not a straight on off to avoid freezing the evaporator. The PCM monitors multiple temperature sensors correlation (AAT, CHT, ECT IAT, MAF...) as applicable. The PCM runs this logic after an engine off and a calibrated soak period, typically 6 to 8 hours. This soak period allows the Ambient Air Temperature (AAT) sensor and the other temperature sensors to stabilize and not differ by greater than a calibrated value, typically 18ºC (32.4ºF). If a sensor input is found to be reporting a temperature imbalance the PCM does not allow the A/C clutch to engage.

 

I know there's a good reason for this, but sometimes these things make me yearn for the time when I flipped a switch and my AC came on regardless of the status of my passenger side mirror.

 

For any future readers with an Ambient Air Temperature Sensor issue causing your AC to stop working check a small sensor located in the front grille of your truck. I ran into a similar issue with a completely unrelated install which drove me crazy and when I disconnected this sensor, cleaned it, knocked it around a little and reconnected it , suddenly my AC worked again and has been working since.

(Ambient Air Temperature Sensor)
See attached PDF

 

During the 2018 production the AAT was moved from the front grille area to the right hand exterior rear view mirror.

 

Sorry if im stating the obvious but want to make sure i understand.

You have a 2020 so that means the AAT is in the passenger side mirror. You do NOT have the mirror plugged in so your AAT isnt plugged in. So your AC isnt working right?

If thats all correct, then yes, the AC needs the AAT to be plugged in

 

Good to know, I didn't know that .. thanks for the insight.