Outside Air Temperature Discrepancy

[pottslaw]

The ambient temp sensor must be influenced by the heat under the hood. It said 127 in my driveway but that is in the shade when I get home so there is no way that is accurate. I got out my IR temp meter and measured 104 degrees at the closed louvers. Measured the pony emblem and it was 117 degrees. Started the car to open the louvers and pop the hood and measured 117 at the radiator (portion exposed through the louvers) and 132 degrees in the front compartment area. No way any ice is going to last very long in there so the shrimp feast is going to have to wait until the fall.

Lastly. Range impact at these extreme temps is 20%. My normal range is 300 miles if the temperature is 105 or less. 115 degrees or more and range drops to around 240 miles looks like...

Thank for all of the helpful replies. If the MME is reading the temperature close to the pavement and managing the cooling for the battery appropriately, then I'll just have to get used to it. It is certainly different from our 2018 Ford Edge.

I haven't seen a significant decrease in range with the Phoenix heat, but the High Temperature warning message has become a familiar sight.

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[pottslaw]

This has been my experience too. It seems the temperature sensor updates relatively slowly.

I think it is very common to get an off-the-chart high reading in any car if you have parked in the sun when you first turn it on, but OP noted in one of his posts that it seems to last while he is driving.

For me, however, the temperature corrects itself after a few minutes of driving. For example, when I drove my Mach-E on Sunday at midday, it was in the high 80s/low 90s in Los Angeles, but I distinctly remember that the Mach-E was showing only 67 degrees. It stayed at 67 degrees until I was driving for a minute or so and was about a mile from my house when it started to jump up by several degrees ever couple of seconds before it stabilized in the high 80s.

The photos I posted were taken while driving in suburban Phoenix traffic. I think the idea that the outside temperature that is being reported is the temperature close to the pavement (and therefore close to the batteries) makes sense. It is hot here in Phoenix, but 129 degrees is Death Valley, not Phoenix!

 

[Scarpia]

I think the idea that the outside temperature that is being reported is the temperature close to the pavement (and therefore close to the batteries) makes sense.

It may be a plausible explanation, but I disagree that it makes sense. The temperature readout on the dash of a car is commonly accepted to be the outside temperature. It's a damn thermometer to tell us what the weather is like! If we need to contort into a pretzel to explain why the temperature is reading 20 degrees hotter than the *actual* outside temperature, something is wrong.

 

[Kamuelaflyer]

Here is where I park at the office.
Crazy hot!

Dude, you’re not down the street from hell, you’re it’s next door neighbor.

 

[SnBGC]

Dude, you’re not down the street from hell, you’re it’s next door neighbor.

Right?
Those parking spaces are located in between warehouses so it turns in to a little bit of an oven because the West Building gets the morning sun and the East Building gets the afternoon sun. Both radiate the heat back to the space in between.
This is the same place where we install EVSE demo units, signs and light fixtures. If they survive in there.....then they are pretty good for almost any application we can think of in the valley.

Only condition that is worse is the top of high rise buildings downtown. Being on the roof of those buildings is brutal during the summer. I mean you get 5 or 10 minutes up there and then you have to get off or risk passing out from the heat.

 

[Marcjacal]

First comment is I wonder how many mme owners there are in the Phoenix area? I’m very far Northwest and I’ve seen one other on the road in my seven months of ownership. It’d maybe be nice to get together and compare notes. Have a club maybe.
Next, I’ve seen the exact same issue. I just ignore it, or take off 10 degrees or so. It sure is hot here!
I’ve seen very little change in my range with this heat and the car drives great. The charger absolutely fails in this heat tho. Either it faults completely, or I get a constant amber light and it charges maybe 10 miles per hour. I bought another charger and the new one (Grizzl-e) works great. Works first time all the time, although It’s a shame that makes the cost of the car go up by a few hundred dollars
I have two questions regarding the heat though. 1. My fan makes a frighteningly loud noise when the car is very hot. Is that Ok? 2. Is it OK to just sit parked, in the heat, with the car & AC running for 10 minutes or so? The fan just screams, and it just makes me wonder if I’m frying things by idling the car when it’s 112. Thanks for the time. Really enjoy my car, and this is a fun forum.

 

[SnBGC]

First comment is I wonder how many mme owners there are in the Phoenix area? I’m very far Northwest and I’ve seen one other on the road in my seven months of ownership. It’d maybe be nice to get together and compare notes. Have a club maybe.
Next, I’ve seen the exact same issue. I just ignore it, or take off 10 degrees or so. It sure is hot here!
I’ve seen very little change in my range with this heat and the car drives great. The charger absolutely fails in this heat tho. Either it faults completely, or I get a constant amber light and it charges maybe 10 miles per hour. I bought another charger and the new one (Grizzl-e) works great. Works first time all the time, although It’s a shame that makes the cost of the car go up by a few hundred dollars
I have two questions regarding the heat though. 1. My fan makes a frighteningly loud noise when the car is very hot. Is that Ok? 2. Is it OK to just sit parked, in the heat, with the car & AC running for 10 minutes or so? The fan just screams, and it just makes me wonder if I’m frying things by idling the car when it’s 112. Thanks for the time. Really enjoy my car, and this is a fun forum.

So it kinda depends on which build you have. If you have a 2021 Job 1 car that hasn't received the 21P22 software enhancements then you can sit in the car with A/C running without much concern. The temp reading on the Sync screen might hit 130-133F but should stabilize.

If you have a later build or got the enhancements then don't sit still with A/C running in 115F for more than 5-10 minutes because the car isn't able to generate enough air flow through the louvers so the car has to be moving. 40 mph is enough to cool things down. If you see 138-142F on the display then you should get moving and keep moving until the temps drop to 112F on the screen before shutting off the car.

 

[pottslaw]

So it kinda depends on which build you have. If you have a 2021 Job 1 car that hasn't received the 21P22 software enhancements then you can sit in the car with A/C running without much concern. The temp reading on the Sync screen might hit 130-133F but should stabilize.

If you have a later build or got the enhancements then don't sit still with A/C running in 115F for more than 5-10 minutes because the can isn't able to generate enough air flow through the louvers so the car has to be moving. 40 mph is enough to cool things down. If you see 138-142F on the display then you should get moving and keep moving until the temps drop to 112F on the screen before shutting off the car.

I'm the OP so this reply is especially interesting.

I have a Job 1 car with the 21P22 software update. I understood the update was intended to reduce the excessive fan noise during charging. Did it also reduce my ability to idle the car (or to sit in traffic) with the AC running? I had not heard about that.

It's been 110F to 115F degrees in Phoenix this month, and as noted in my original post, the temperature display does not accurately reflect the ambient air temperature. I've seen high 120's on the display in normal East Valley traffic this week. Have others found that you need to see 112F or less on the screen before shutting off the car? I'll keep better track of it going forward, but I am pretty sure I regularly pull into the garage in the late afternoon this time of year with a displayed temperature above 115F.

As discussed elsewhere, the ideal solution would be for the car to cool the battery while plugged in without charging, but that's not likely to happen.

Thanks.

 

[HuntingPudel]

Mine read kind of whacky for a couple of days a few weeks back. It was pretty consistent with expected temperatures in the mid to high 90s, then one day it was reading 117 on US 101 in San Carlos. The odd thing is that it was reading 97 in the parking lot at work in Redwood City. Parking. Lot at work was recently repaved so it’s pitch black. Anyhow, it behaved this way for 2 days then went back to reading how I thought it should read,. My car is stupid. I know my dog is smarter than my car, since he’s smarter than a lot of people I know.

 

[SnBGC]

I'm the OP so this reply is especially interesting.

I have a Job 1 car with the 21P22 software update. I understood the update was intended to reduce the excessive fan noise during charging. Did it also reduce my ability to idle the car (or to sit in traffic) with the AC running? I had not heard about that.

It's been 110F to 115F degrees in Phoenix this month, and as noted in my original post, the temperature display does not accurately reflect the ambient air temperature. I've seen high 120's on the display in normal East Valley traffic this week. Have others found that you need to see 112F or less on the screen before shutting off the car? I'll keep better track of it going forward, but I am pretty sure I regularly pull into the garage in the late afternoon this time of year with a displayed temperature above 115F.

As discussed elsewhere, the ideal solution would be for the car to cool the battery while plugged in without charging, but that's not likely to happen.

Thanks.

I don't think we will ever know what changes Ford made to the software. All I can say for certain is that I never had any issues last summer while parked with A/C running and never saw anything above 133F on the screen. While using my scan tool, the A/C compressor appeared to Max out at 4000 rpm.

This year I have yet to see 4k rpm so I am guessing Ford slowed it down a bit. The cooling fan doesn't blow as hard this year as last year either. It seems to for a moment or two but then slows down a bit. Most of the time it is fine, car still performs same as before except for one scenario.

If driving in ambient temps over 113F and caught in a traffic jamb moving at a slow crawl then the car will start to over heat. When that happens, the A/C to the cabin is limited and starts to blow warm air. I presume this is because the battery takes priority over the passenger compartment. Temps on the Sync screen will exceed 140F during this process.

This was never an issue last year so something changed. I can only presume the change is software related but I don't know that for sure. Maybe last summer was mild compared to this year?

At any rate, the first time it happened to me this year.....the display was reading around 120F like normal and then I got caught in a traffic jam. I was on an incline in 1PD and watched the temp display count up from 123F to 142F in the span of 60 seconds or so. Then the A/C started blowing warm and I was starting to panic. I turned off 1PD and the temps stabilized and even began falling. It dropped to around 135F or so and then traffic started moving again. Once I got up to 40-45 mph then the temps fell like a rock. All the way down to 112F where it remained for the rest of my 40 min drive.

I don't know what temp the car needs to be plugged in to cool. Seems like anything in the 115F and above displayed on the Sync screen is a good bet the car will start cooling when plugged in. Doesn't happen every time though. So I am not really that certain. ??

 

[Ming]

It's been 110F to 115F degrees in Phoenix this month, and as noted in my original post, the temperature display does not accurately reflect the ambient air temperature.

No car would display the "correct" ambient temperature you think of. The temperature from weather report uses a specific setup - typically shaded 1 meter or so above grass area. Your car with a temperature sensor 1 foot over a pavement under the sun will measure much higher temperature. It is the true temperature at where the sensor is. The car is not smart enough to know how much it is higher than you "correct ambient" temperature.

 

[pottslaw]

No car would display the "correct" ambient temperature you think of. The temperature from weather report uses a specific setup - typically shaded 1 meter or so above grass area. Your car with a temperature sensor 1 foot over a pavement under the sun will measure much higher temperature. It is the true temperature at where the sensor is. The car is not smart enough to know how much it is higher than you "correct ambient" temperature.

I know how NOAA and others measure "official" air temperature. That's not what we're talking about. The reason is Ford's placement of the temperature sensors near the pavement to monitor the battery health on the Mach E, while reporting that temperature to the driver as the air temperature one would expect to see displayed in any other Ford. Put another way, the temperature below the car is irrelevant to the driver, and inconsistent with the way Ford reports outside air temperatures in its ICE vehicles.

Separately. as you can see from the other replies, Phoenix drivers are reporting displayed temperatures of 135 to 142 degrees. The car apparently overheats at those temperatures. That is a much bigger issue than the temperature variances I reported last year when I started this thread. If I knew the 21P22 software update would increase the likelihood that my car will overheat in Phoenix in the summer, I would not have done the update in the first place.

 

[SnBGC]

No car would display the "correct" ambient temperature you think of. The temperature from weather report uses a specific setup - typically shaded 1 meter or so above grass area. Your car with a temperature sensor 1 foot over a pavement under the sun will measure much higher temperature. It is the true temperature at where the sensor is. The car is not smart enough to know how much it is higher than you "correct ambient" temperature.

The temp displayed on the Sync screen appears to get its data from the temp sensor under the good vs the sensor in the bumper above the louvers. Not sure why Ford did that.

I have measured it many times. The temp displayed on the screen matches the temp of the front trunk compartment and not the ambient.

That being said, now that I know this. I can use the temp display on the screen to determine when the drive train is adequately cooled or when it might be overheating. If they get too hot then I can adjust my driving accordingly. Same as when driving an ICE and the temps approach the limit.

 

[ZuleMME]

This thread is hilariously bad, the ford implementation sucks. Every car I’ve ever had was better at giving a general outdoor temperature for the drivers use. Yes, the car should know how hot the road is under the car, but that’s not what it should display to the occupants of the car on the screen. On my trip to Vegas a few weeks back it was 111 to 113 in the city that week. Car was always reading 120 to 145. Even when driving 65+ on the freeway. It’s a joke. At more reasonable temperatures under 100 it seems more accurate. I suspect they have a calibration problem at the upper end.

 

[SnBGC]

This thread is hilariously bad, the ford implementation sucks. Every car I’ve ever had was better at giving a general outdoor temperature for the drivers use. Yes, the car should know how hot the road is under the car, but that’s not what it should display to the occupants of the car on the screen. On my trip to Vegas a few weeks back it was 111 to 113 in the city that week. Car was always reading 120 to 145. Even when driving 65+ on the freeway. It’s a joke. At more reasonable temperatures under 100 it seems more accurate. I suspect they have a calibration problem at the upper end.

And of course you know the ambient temp is never 145F so that reading on the screen is not coming from that sensor out front.

I agree, that reading on the screen should be ambient but it is not. It is the temp under the hood behind the radiator.

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