Temperature reading?

[alexgorod]

Went to the garage to plug it in and checked the temperature reading - it's 48. Phone shows that it's 31 outside.

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[HuntingPudel]

Can't say for sure what the pudel thinks, but it is probably colder near the garage door.

Yeah, I was thinking if he backed in and the temp sensor is at the front bumper the temp by the garage door is probably lower than in the rest of the garage. That thought is moot now. ?‍?

 

[Crilly]

Chuck, I am with you. When I got mine last February it showed the temp ( 55*) in my garage. Now it shows outside temp. Same as my Iphone.

 

[JimmyMachE]

I think there are more temperature sensors in the car. Car Scanner Elm Obd2 app shows three ambient temperatures: exterior, outside and outdoor (BCM). Each is slightly different, so the signal is probably not coming from a single sensor.

 

[breeves002]

Straight from the WSM. Check out the last paragraph:
Outside Air Temperature

The Ambient Air Temperature (AAT) sensor is hardwired to the PCM through separate input and return circuits. The PCM provides a reference voltage to the Ambient Air Temperature (AAT) 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 Ambient Air Temperature (AAT) sensor than the actual 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 Ambient Air Temperature (AAT) sensor.

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It's not supposed to update in the garage. It won't start updating again until you drive. It's using the temperature that it last was reported before you parked it (outside). It updates less at lower speeds and does more averaging to avoid heat soak. Sit in your car for 5 minutes in the garage with it on and I bet it updates to garage temp.

 

[markboris]

I think there are more temperature sensors in the car. Car Scanner Elm Obd2 app shows three ambient temperatures: exterior, outside and outdoor (BCM). Each is slightly different, so the signal is probably not coming from a single sensor.

There are many ambient temperature sensors inside the car. Some monitor the outside air temp coming in the car but most monitor the inside air temps for the HVAC system. Front Inside sensor 1, 2, 3, EATC inside car temp sensor, Footwell air discharge temp left and right sensors, dash air register discharge left and right sensors, outside air inlet temp sensor, etc. The BCM might call them exterior, outside or outdoor sensors but there is only one outside ambient air temp sensor and it has nothing to do with the BCM. It goes directly to the PCM.

I was just writing this as Sam posted the above. Anyway, there is only one outside ambient air temp sensor on all Ford's that I know of.

 

[Chuck518]

Are you using AA and seeing that temp??

What's AA?

 

[Chuck518]

Straight from the WSM. Check out the last paragraph:
Outside Air Temperature

The Ambient Air Temperature (AAT) sensor is hardwired to the PCM through separate input and return circuits. The PCM provides a reference voltage to the Ambient Air Temperature (AAT) 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 Ambient Air Temperature (AAT) sensor than the actual 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 Ambient Air Temperature (AAT) sensor.

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It's not supposed to update in the garage. It won't start updating again until you drive. It's using the temperature that it last was reported before you parked it (outside). It updates less at lower speeds and does more averaging to avoid heat soak. Sit in your car for 5 minutes in the garage with it on and I bet it updates to garage temp.

OK, this makes sense. I will try your experiment!

Is this system unique to the MME, or does it also apply to Ford's internal combustion engines as well? Is it industry-wide?

Where is the sensor?

What does PCM stand for?

 

[markboris]

OK, this makes sense. I will try your experiment!

Is this system unique to the MME, or does it also apply to Ford's internal combustion engines as well? Is it industry-wide?

Where is the sensor?

What does PCM stand for?

I don't think you read my post #8 . This system is not unique to the MME. It is the same system Ford uses in most all of their other cars and trucks.

 

[Thor2j]

What's AA?

Android auto. Or Apple carplay for that matter

 

[Chuck518]

I don't think you read my post #8 . This system is not unique to the MME. It is the same system Ford uses in most all of their other cars and trucks.

You're right, I had not read it; I just did, and it was most informative. Thanks. Now I understand it. There's no fault in my system, I just wasn't properly understanding what I was seeing.

But I do still have one question: When I put a trip into my Fordpass and send it to the car, the display I see seems to take into account elevation gains. For example, when I drive from Albany, NY, to my home in the Adirondacks, involving an elevation gain of 1,500 ft., the estimated reserve in the battery is uncannily accurate; the same is true when I go down to Albany. So I conclude that the calculation is using elevation differences as data points, suggesting that it accesses GPS information. Is this reasoning correct?

There is also usually a 10 to 20F temperature difference between my home and Albany. Do the algorithms have access to destination temperatures in making the calculations?

 

[Maquis]

Straight from the WSM. Check out the last paragraph:
Outside Air Temperature

The Ambient Air Temperature (AAT) sensor is hardwired to the PCM through separate input and return circuits. The PCM provides a reference voltage to the Ambient Air Temperature (AAT) 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 Ambient Air Temperature (AAT) sensor than the actual 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 Ambient Air Temperature (AAT) sensor.

---------
It's not supposed to update in the garage. It won't start updating again until you drive. It's using the temperature that it last was reported before you parked it (outside). It updates less at lower speeds and does more averaging to avoid heat soak. Sit in your car for 5 minutes in the garage with it on and I bet it updates to garage temp.

Based on my experience, this is pretty much spot-on.

One exception, I have seen ridiculously high readings when starting the car up when it’s been parked in the hot sun. I remember seeing 113 displayed when it was mid-90s ambient. Maybe this got fixed in an update, but I wont be able to check it out until next summer.

 

[markboris]

You're right, I had not read it; I just did, and it was most informative. Thanks. Now I understand it. There's no fault in my system, I just wasn't properly understanding what I was seeing.

But I do still have one question: When I put a trip into my Fordpass and send it to the car, the display I see seems to take into account elevation gains. For example, when I drive from Albany, NY, to my home in the Adirondacks, involving an elevation gain of 1,500 ft., the estimated reserve in the battery is uncannily accurate; the same is true when I go down to Albany. So I conclude that the calculation is using elevation differences as data points, suggesting that it accesses GPS information. Is this reasoning correct?

There is also usually a 10 to 20F temperature difference between my home and Albany. Do the algorithms have access to destination temperatures in making the calculations?

That I cannot answer as I don't know if Sync is using elevation differences as data points. It is very possible it is and I know the GPS info is constantly being used by Sync.

As far as the having access to destination temperatures, no, it does not. The only temp it uses and monitors is from the ambient temp sensor at the front bumper.

 

[ShadowCVL]

So, annecdotally, if I start the car with my phone in my pocket it shows outside temperature. If I just run down to pull the car out of the garage with the fob it shows the garage temperature.

It may be getting data from your phone at time of start. I say this because when I started the car yesterday it was 39 F out, it was almost 70 in the garage because it was 68 the day before. the car turned the heat on and when i got in it read 38.

 

[markboris]

So, annecdotally, if I start the car with my phone in my pocket it shows outside temperature. If I just run down to pull the car out of the garage with the fob it shows the garage temperature.

It may be getting data from your phone at time of start. I say this because when I started the car yesterday it was 39 F out, it was almost 70 in the garage because it was 68 the day before. the car turned the heat on and when i got in it read 38.

Chris, I don't understand how your car can show the outside temp that is on your phone when the two don't communicate with each other. Not that I don't believe you but this is very strange.

I just went out in my garage where it is 64 and my phone shows 45 temp outside (which it is). I only use PAAK so no key fob is present. Got in, started the car and it shows 64, the temp in the garage not the outdoor temp. I don't know what to tell you.