Exterior ambient temp sensor reset?

[MadMatt3883]

Does anybody know how to reset the temp sensor?  Outside temperature readings are  usually 20 degrees off when the truck has been parked outside. Once I start driving the reading drops but still reads 6-10 degrees hotter than it probably should. I’ve already tried holding the AC and recirculate buttons which does nothing. 

[Transient]

No point in resetting it, imo.  It's not a thermostat or thermometer.  It's a thermistor.  Car manufacturers use thermistors because they're cheaper.  The problem is, they're also less accurate.  The reading you're getting is of the air temperature under the hood, which is why it's hotter when you first start your truck on a hot day and then reads a few degrees higher then the electric sign out front of a bank that gives you time and temperature that you pass while driving down the road.  The only true fix to the issue plaguing all vehicles in the road is to upgrade the component used and relocate it for an accurate reading.  Good luck with that.

[newdude]

How it works:

 

Outside Air Temperature

 

The Ambient Air Temperature Sensor is located in the Passenger Outside Rearview Mirror and varies it’s resistance with temperature. The Engine Control Module (ECM) reads the resistance value to determine temperature. The time of and rate of the temperature update is based on an algorithm in the Engine Control Module (ECM) software. Factors such as, last reading, current reading, length of time vehicle is been off/on, power mode, vehicle speed, driven distance, and sensor location are all considered by the Engine Control Module (ECM) to know when to update the displayed temperature on the Info Display Module. For example, if the sensor is located near the engine compartment, and the vehicle has been turned off for only 10 minutes then restarted, the ECM will wait until the vehicle is driven to get more accurate air flow across the sensor before it updates the display.

[MadMatt3883]

Will replacing it even make a difference?  It’s in the rear view mirror, looks easy to swap out and the part is only a few dollars.  Just figured I would attempt to reset it before swapping it. 

[Bikerjon]

Replacing it will probably not make it accurate if this is what you are trying to do. A thermistor is just not very accurate.

[Muddturtle1231]

19 hours ago, Transient said:

No point in resetting it, imo.  It's not a thermostat or thermometer.  It's a thermistor.  Car manufacturers use thermistors because they're cheaper.  The problem is, they're also less accurate.  The reading you're getting is of the air temperature under the hood, which is why it's hotter when you first start your truck on a hot day and then reads a few degrees higher then the electric sign out front of a bank that gives you time and temperature that you pass while driving down the road.  The only true fix to the issue plaguing all vehicles in the road is to upgrade the component used and relocate it for an accurate reading.  Good luck with that.

It is not reading the temp under the hood.  It is attached to the underside of the passenger side mirror, so it is reading whatever heat is radiating up from whatever surface you are parked on.