Where is external temperature sensor on the Bronco?

[flip]

Outside Air Temperature

The Outside Air Temperature (OAT) sensor is located in the driver side mirror, and hardwired to the PCM through separate input and return circuits. The PCM provides a reference voltage to the Outside Air Temperature (OAT) sensor and monitors the change in voltage resulting from changes in resistance as determined by outside air temperature.

The PCM sends the ambient air temperature data to the HVAC module where the temperature data is filtered. The HVAC module sends the filtered outside air temperature data to the IPC to display the outside air temperature.

The HVAC module is programmed to update the messaged outside temperature data at different rates depending on several criteria to prevent false temperature displays due to a condition known as heat soaking. Heat soaking is where the outside air temperature is hotter in the location of the Outside Air Temperature (OAT) sensor than the actual outside air temperature.

The outside air temperature display update strategy requires a starting temperature to update from. This starting temperature is controlled based on the length of time the engine is off and the engine temperature. When the engine has been off for longer than 4 hours, the update strategy begins with the unfiltered ambient air temperature input to the PCM . If the engine has been off for less than 4 hours, and the engine coolant temperature is less than 30° C (86° F), the update strategy begins with the filtered ambient air temperature equal to the unfiltered ambient air temperature. If the engine has been off for less than 4 hours, and the engine coolant temperature is greater than 30° C (86° F), the update strategy begins at the stored previous outside air temperature value.

When the sensed outside temperature rises and the vehicle speed is above 32 km/h (21 mph), the outside air temperature display updates after approximately 90 seconds. As the vehicle speed increases, the outside air temperature display updates at a faster rate that is proportional to the increase in vehicle speed. Once the vehicle speed exceeds 80 km/h (50 mph), the display updates without any delay. If the vehicle speed drops below 32 km/h (21 mph), the update delays reset. When the sensed outside temperature drops, the display updates more quickly following the drop experienced by the Outside Air Temperature (OAT) sensor.

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[BruceAZ]

Outside Air Temperature



When the sensed outside temperature rises and the vehicle speed is above 32 km/h (21 mph), the outside air temperature display updates after approximately 90 seconds. As the vehicle speed increases, the outside air temperature display updates at a faster rate that is proportional to the increase in vehicle speed. Once the vehicle speed exceeds 80 km/h (50 mph), the display updates without any delay. If the vehicle speed drops below 32 km/h (21 mph), the update delays reset. When the sensed outside temperature drops, the display updates more quickly following the drop experienced by the Outside Air Temperature (OAT) sensor.

This is an old thread, but thanks to the search function I found it and thanks to Flip for the explanation.
I was 4-wheeling a week ago for a couple days and noticed that the outside temp display did not change until I got back on a road and at a decent speed. I figured it had something to do with speed, but didn't know where the sensor is or how it worked. The only thing I would say is that "below 21mph the update delays reset" would seem to better read "below 21mph the update blocks reset". I would go literally for hours with no change in the display even tho the outside temperature changed by 20-30 degrees.
Nice to know the thing is working as designed, even tho I would prefer a more accurate display at low speeds.

 

[Bronco_Lyfe]

Ambient Air Temperature Sensor
Special Tool(s) / General Equipment

Flat-Bladed Screwdriver

Removal

NOTE: Removal steps in this procedure may contain installation details.

1. • Using a suitable tool, pry and detach the ambient air temperature sensor bezel from the LH exterior mirror housing.
     Use the General Equipment: Flat-Bladed Screwdriver
   • Disconnect the ambient air temperature sensor electrical connector and remove the ambient air temperature sensor.

Installation

1. To install, reverse the removal procedure.
   • If replacing the ambient air temperature sensor a reset must be performed.

How do I do the reset?

 

[flip]

Unhook battery?

 

[Robs]

Did the temp change while driving or after it was parked? The ambient air temp sensor is in the driver's mirror housing. I asked about the temp difference because it will definitely show a higher temp after sitting in the sun after setting. You'll have to drive it, don't quote me on this, but I think it was 30MPH before it starts recalculating again.


Ambient Air Temperature (AAT) Sensor

The Ambient Air Temperature (AAT) sensor is an input to the PCM . If the outside air temperature is below approximately 0°C (32°F), the PCM does not allow the A/C compressor clutch to engage.

The PCM sends raw ambient air temperature data to the HVAC control module. The HVAC control module filters the raw data, sends it to the APIM and the touchscreen displays the outside temperature.

Well that’s pretty silly (below 32 and the ac won’t work????). We use ac but with heat to eliminate inside fogging during cold weather.

 

[adam1991]

Well that’s pretty silly (below 32 and the ac won’t work????). We use ac but with heat to eliminate inside fogging during cold weather.

I agree, and I believe that if that's any sort of official documentation, it's wrong.

Most mfrs anymore always run the AC (scroll compressors are wonderful) even if they don't light up the button. They CERTAINLY run the AC when the front defroster is on. In fact, I wouldn't be surprised to hear that's a federal regulation--given the ignorance that abounds and people assuming "why would I run the AC, it's cold outside" despite the copious amounts of moisture the meatbags in the seats exhume, moisture that must be removed from the car or else it clings to the cold windows and makes them opaque.

And we know, left to their own devices people will happily drive with opaque windows. Shoot, now they don't even aim their eyeballs at the windows--the phone has taken that over.

 

[Ducati1098]

I agree, and I believe that if that's any sort of official documentation, it's wrong.

Most mfrs anymore always run the AC (scroll compressors are wonderful) even if they don't light up the button. They CERTAINLY run the AC when the front defroster is on. In fact, I wouldn't be surprised to hear that's a federal regulation--given the ignorance that abounds and people assuming "why would I run the AC, it's cold outside" despite the copious amounts of moisture the meatbags in the seats exhume, moisture that must be removed from the car or else it clings to the cold windows and makes them opaque.

And we know, left to their own devices people will happily drive with opaque windows. Shoot, now they don't even aim their eyeballs at the windows--the phone has taken that over.

Lol it’s not wrong.
You can datalog any vehicle and easily see that the compressor will not turn on below 32 degrees. Even if you request A/C it will not work.
It purposely does this to prevent damage to the A/C system. This is nothing new at all.
Just because you’re in defrost mode doesn’t mean it’s able to use the A/C.

You can find the exact same official information in the workshop manual for every Ford vehicle. Some older vehicles even shut it off at a much higher temperature. For example, this is from a 2010 F150:

 

[MC1313]

Outside Air Temperature

The Outside Air Temperature (OAT) sensor is located in the driver side mirror, and hardwired to the PCM through separate input and return circuits. The PCM provides a reference voltage to the Outside Air Temperature (OAT) sensor and monitors the change in voltage resulting from changes in resistance as determined by outside air temperature.

The PCM sends the ambient air temperature data to the HVAC module where the temperature data is filtered. The HVAC module sends the filtered outside air temperature data to the IPC to display the outside air temperature.

The HVAC module is programmed to update the messaged outside temperature data at different rates depending on several criteria to prevent false temperature displays due to a condition known as heat soaking. Heat soaking is where the outside air temperature is hotter in the location of the Outside Air Temperature (OAT) sensor than the actual outside air temperature.

The outside air temperature display update strategy requires a starting temperature to update from. This starting temperature is controlled based on the length of time the engine is off and the engine temperature. When the engine has been off for longer than 4 hours, the update strategy begins with the unfiltered ambient air temperature input to the PCM . If the engine has been off for less than 4 hours, and the engine coolant temperature is less than 30° C (86° F), the update strategy begins with the filtered ambient air temperature equal to the unfiltered ambient air temperature. If the engine has been off for less than 4 hours, and the engine coolant temperature is greater than 30° C (86° F), the update strategy begins at the stored previous outside air temperature value.

When the sensed outside temperature rises and the vehicle speed is above 32 km/h (21 mph), the outside air temperature display updates after approximately 90 seconds. As the vehicle speed increases, the outside air temperature display updates at a faster rate that is proportional to the increase in vehicle speed. Once the vehicle speed exceeds 80 km/h (50 mph), the display updates without any delay. If the vehicle speed drops below 32 km/h (21 mph), the update delays reset. When the sensed outside temperature drops, the display updates more quickly following the drop experienced by the Outside Air Temperature (OAT) sensor.

Does this sensor impact any engine settings? IE fuel or timing?

 

[cmtaz]

If you remove that sensor, when you replug it in it will trip a "boatload" of codes including a CEL. Mine was falling out, and the dealership removed it to order a new one, then they plugged it back in. I barely made it off the lot when I noticed the CEL. Took it back and they said they forgot to clear the codes.......

 

[Desmolicious]

Hey my first search result! My 1.5 day old Bronco HE w 46 miles on it gives an outside reading of 78 even though today at that time it was 67. City driving, maybe at 40mph.

I will put miles on this lump first before I panic and rush to the dealer.

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