# Where is the outside air temperature sensor? Mine read 5 deg too high



## bartonmd (Jun 30, 2011)

Dale_K said:


> My outside air temp reading is always about 4-5 degrees too high. I was thinking about replacing the sensor myself but I couldn't even find it. On my GM truck it is on a bracket in front of the A/C condenser but I looked all over the front of my new Cruze and I don't see it.
> 
> Anybody know where it is?
> 
> Anybody else have the same problem with the temp display being inaccurate and too high? This is not the normal delay when driving away from a hot parking spot - it's just plain wrong, even after driving for many miles.


IIRC, it's on the driver's side fog light surround... Because it's so close to the road, it will read a bit higher than the ambient, due to the heat coming off the road surface...

Mike


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## Quazar (Apr 28, 2011)

Like bart said, its always going to read high during the summer where it is located.


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## Dale_K (Jul 16, 2011)

Thanks. I just looked and now I see it. I guess you'd get to it by taking off the fender liner.

You could be right about the location being why it reads too high but the location on my GMC is only about a foot higher and it reads accurately.


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## ericinaz (Jul 18, 2011)

I have the same issue. I just turned my leased 2008 Malibu in and the outside temp was always spot on. Yesterday in my new Cruze LTZ RS it was 111 outside and the temp read 122. It seems to always be 5-10 degs F higher then it should. It's always hot here in Phoenix, and I don't need my car to tell me it's hotter...


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## Quazar (Apr 28, 2011)

ericinaz said:


> I have the same issue. I just turned my leased 2008 Malibu in and the outside temp was always spot on. Yesterday in my new Cruze LTZ RS it was 111 outside and the temp read 122. It seems to always be 5-10 degs F higher then it should. It's always hot here in Phoenix, and I don't need my car to tell me it's hotter...


Where its located has a big impact, as well as the color of your car. FYI a black car will give off heat in the sun 20 - 50F hotter than the air temperature. When a car is heating up that much, the air around the car is going to be hotter. The thermostat will experiance heat soak and take even longer to cool off. 

In the morning, before the sun is up my thermo is within 1 - 2 degrees so it is not that inaccuate. 

The reality is, it was 122 degrees, or close there around your car. You could take a independent thermostat and measure just to see for yourself.


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## ericinaz (Jul 18, 2011)

Quazar said:


> Where its located has a big impact, as well as the color of your car. FYI a black car will give off heat in the sun 20 - 50F hotter than the air temperature. When a car is heating up that much, the air around the car is going to be hotter. The thermostat will experiance heat soak and take even longer to cool off.
> 
> In the morning, before the sun is up my thermo is within 1 - 2 degrees so it is not that inaccuate.
> 
> The reality is, it was 122 degrees, or close there around your car. You could take a independent thermostat and measure just to see for yourself.


I totally agree that it was that hot around the car as the pavement is super heated along with the car body. I guess that when providing the outside ambient temp one would assume it would be the true air temp and not partly based on the ground temp. Even after 45 minutes of freeway driving it's still high. The reason I brought up the malibu was that on a 115* day sitting in the sun it still showed the true "air" temp after only a few miles. I just feel that GM failed in their placement of the sensor as it's thrown off by the surface heat.


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## NBrehm (Jun 27, 2011)

mine has been pretty accurate, within 2 degrees or so


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## Quazar (Apr 28, 2011)

ericinaz said:


> I totally agree that it was that hot around the car as the pavement is super heated along with the car body. I guess that when providing the outside ambient temp one would assume it would be the true air temp and not partly based on the ground temp. Even after 45 minutes of freeway driving it's still high. The reason I brought up the malibu was that on a 115* day sitting in the sun it still showed the true "air" temp after only a few miles. I just feel that GM failed in their placement of the sensor as it's thrown off by the surface heat.


One thing people seem to fail to take into account is the engineering of this car, especially the ECO (not sure what model you have) is that one way GM reduced the drag on this car is by minimizing the airflow into the body of the car.

The cruze has far less airflow and has a much lower coefficient of drag than the Malibu. (.285-.30 compared to .34) These engineering changes make placement of items, like exterior temperature sensors more complicated. It is not necessarily poor engineering, its compromise to accommodate multiple features with multiple variables. 

In addition, the temperature that the “weather channels” say is not affected by heat rising off say blacktop or direct sun; official temperatures are usually taken from points at 10 feet above ground and in the shade. Within 3 feet of the ground and in direct sun, temperatures can be as hot as 60F above official temps. 

The only way to be able to tell how accurate the air thermostat is would be to have a separate one take the temp in the area you are at around ground level and compare. This is also why people who live different areas of the country/world will have different perceptions on how accurate the temperature sensor is. 

Hopefully this sheds some light on how complicated getting temperature readings are from both an engineering and logistical standpoint.


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## SilverCruzer (Nov 30, 2010)

Quazar said:


> Like bart said, its always going to read high during the summer where it is located.


 I also noticed direct sun (driving west in afternoon) also boosts it to about 10 degrees too high. Worthless in my opinion.


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## 70AARCUDA (Nov 14, 2010)

SilverCruzer said:


> I also noticed direct sun (driving west in afternoon) also boosts it to about 10 degrees too high. *Worthless in my opinion*.


...an old engineering saying goes: _*BAD* data is worth LESS than *NO* data._


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## Quazar (Apr 28, 2011)

SilverCruzer said:


> I also noticed direct sun (driving west in afternoon) also boosts it to about 10 degrees too high. Worthless in my opinion.


As I said in my other post, direct sun temperatures are hotter then the temperture on Weather.com

All weather temperatures are taken in the shade, there is a great picture of this online, the thermostat shows 80F in the sun, in the shade its 20F.

It's not inaccurate, its reading the temp in the sun.


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## SilverCruzer (Nov 30, 2010)

Quazar said:


> As I said in my other post, direct sun temperatures are hotter then the temperture on Weather.com
> 
> All weather temperatures are taken in the shade, there is a great picture of this online, the thermostat shows 80F in the sun, in the shade its 20F.
> 
> It's not inaccurate, its reading the temp in the sun.


I know...that's my point. Not saying its innaccurate, just worthless. 
MY other car some how does a much better job giving a more "usable" temp by putting the sensor in a spot not affected by direct sun regardless of vehicle orientation. Its still a few higher than my outdoor themometer at the house which I account to being on pavement, but a much better indicator.


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## Dale_K (Jul 16, 2011)

I noticed yesterday evening that the temp seemed about right after the car sat in the garage all day. My home outside thermometer said 91 and so did the Cruze. But it still reads too high in the afternoon sunshine.

Maybe it is the sun but I have a Boxster and it's sensor is equally close to the ground but clipped to the grill opening instead of solidly mounted the way my Cruze is attached to the left side fog light blank off panel (no fogs on my car). The Boxster temp always displays an accurate reading so it's not because the Cruze unit is close to the sun baked road surface. The black plastic fog light blank off panel might be picking up radiant heat. Honestly this is such a minor issue I'm not very concerned. It's funny how it doesn't affect my other vehicles - just the Cruze.


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## Quazar (Apr 28, 2011)

Dale what color is your cruze/boxer


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## Dale_K (Jul 16, 2011)

Both are dark metalic blue. Almost the same color. You can almost see the sensor in the right side radiator grill. I think the Cruze sensor would work better in a flow through air stream.


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## CruzinJB (Jul 31, 2011)

Well it seems like we need to find a location to move the sensor to that it gets the air flow of outside air instead of up under the bumper that heats up setting in the sun. Maybe somewhere around the front grill thats open all the time in all models of the Cruze. A short harness could be made to relocate the position if the wiring that is going to the sensor cannot be relocated to the new position. Any good ideas for this??


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## NBrehm (Jun 27, 2011)

I'm not having an issue with mine, worst it's been off is a degree or 2 once I get driving. Realistically you can put it anywhere your heart desires, if you put it in an area where are flows completely past it it will read low. I guess I just don't need to know if it is 85 or 89 all that much. as long as it is reading like 30 degrees off I'm good with it.


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## TexBru (Mar 23, 2011)

My 2011 Cruze LTZ's outside temp. reads 5-10 degrees above the "advertised" summer temp also. Doesn't sound like it can be fixed either......


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## NYCruze2012 (Jan 16, 2012)

Is it possible that it is picking up some hot air from the engine?

Hoping my Cruze and my Droid 3 are still here to send this message barring any engine fires!


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## TechCruzer (Mar 15, 2012)

I don't see what the big deal is... is a 5 - 10* difference really make that much of a difference? Seems that it is very hot regardless if it reads 100 or 110 the fact remains it is HOT... period! I suppose the temperature sensor at the local Church marquis might be more accurate than my cars, but so what it's hot regardless. Don't leave children, pets, ice cream, disc's, etc. if you don't want any harm to come to what I mentioned especially the 1st two! I for one appreciate what I have in my temp display, but I don't really care if there is 10% variance I'm not going to report it on the 6 o'clock news as an accurate forecast.


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## OnlyTaurus (Mar 20, 2012)

The temp sensor is 10 inches from the ground. Bad design? I think they could've found a better place for it yes. At work, I'm parked on pavement, on a 90 degree day I've seen the temp display almost 130 on a sunny day, because the sensor is reading the heat coming off the pavement. It's doing its job.

Do i think it's a big deal? No lol. The temp will eventually settle while driving(especially highway). It's certainly not worth griping over, no offense. If its that big of a deal, remove the sensor and make your own location for it.

Sent from my DROID BIONIC using AutoGuide.Com Free App


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## NickD (Dec 10, 2011)

Ha, the National Weather Bureau use to call me to learn the exact temperature in my area, but no more with the Cruze.

Shiny highly reflective while car, 2LT that typically reads 5-8*F during these hot summer days. Should I take it back to my dealer or just mentally subtract that error?

Cadillac DeVille was dead on, same deal, ambient temperature thermistor was mounted on a bracket far in front of the condenser in the air stream. Should do that on the Cruze.

Did start to remove the radiator cover so I could clean off the bugs on my condenser. Only to learn, the bumper has to be removed first as there are bolts under that cover. Will save that for a rainy day. Whole front end was designed by a frustrated Chinese puzzle designer, main tool is healthy finger nails. Least its easy to change the headlamp bulbs, on some GM vehicles have to also remove the bumper first. 300 buck job at the dealers, unless you can do it yourself.


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## sndguy (Nov 17, 2011)

The Number One reason I want a temp sensor is in the winter, so I know what the road temp is. Is it icing, or just wet? The closer the temp sensor is to the road, the better. Any other reason for a temp sensor is just a "bell or whistle".


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## sciphi (Aug 26, 2011)

My temp sensor is spot-on. I don't know if it's because it's a black car so it's a blackbody, or because I'm going mostly 45+ mph most of the time.


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## NYCruze2012 (Jan 16, 2012)

sndguy said:


> The Number One reason I want a temp sensor is in the winter, so I know what the road temp is. Is it icing, or just wet? The closer the temp sensor is to the road, the better. Any other reason for a temp sensor is just a "bell or whistle".


 I'm sure when winter comes the situation is going to be completely different and I believe the temperature sensor maybe more accurate. It will pick up a less heat from the engine and less radiant heat from the pavement. Who is with me on this or are my thoughts on this just completely way off?

Hoping my Cruze and my Droid 3 are still here to send this message barring any engine fires!


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## rbtec (Feb 3, 2012)

NYCruze2012 said:


> I'm sure when winter comes the situation is going to be completely different and I believe the temperature sensor maybe more accurate. It will pick up a less heat from the engine and less radiant heat from the pavement. Who is with me on this or are my thoughts on this just completely way off?
> 
> Hoping my Cruze and my Droid 3 are still here to send this message barring any engine fires!


Agree. 


Sent from my Autoguide iPhone app


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## Pruittx2 (Mar 24, 2012)

The paint temp on my Black Suburban, was 165F measured with an infrared laser temp gun, the head liner area, when i opened the door and shoot was 148F and this was on a 105F day here in Mid Michigan a few weeks back.


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## jblackburn (Apr 14, 2012)

My Volvo was always the same way in the summer - always 5-8 degrees hotter than what my phone said for the area. In the winter, it was DEAD ON accurate, though. Mounted in the exact same place as the Cruze.


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## jdubb11 (Mar 14, 2012)

this sensor is a joke. mine is almost always 10 plus degrees off. it does not adjust after driver either. not the biggest deal in the world but if its going to be there shouldnt it be at least in the ballpark. when i bring it in for one of my free oil changes at the dealer ill see if they can do something with it.


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## gman19 (Apr 5, 2011)

Quazar said:


> In addition, the temperature that the “weather channels” say is not affected by heat rising off say blacktop or direct sun; official temperatures are usually taken from points at 10 feet above ground and in the shade. Within 3 feet of the ground and in direct sun, temperatures can be as hot as 60F above official temps.


This ^^...

And this from NWS Cooperative Observer Program 

Note the last statement...noting our temperature sensor is about a foot or so off the pavement.
[h=1]Proper Siting[/h]The COOP network has provided climate and weather data for over 100 years. Consistency of the measurements is an attribute of the network, and it has been maintained by rare and/or gradual change, and established standards for exposure, of instruments over the life of the network. In order to preserve the integrity of the network, NWS has established standards for equipment, siting, and exposure. 

*Temperature sensor siting: *The sensor should be mounted 5 feet +/- 1 foot above the *ground.* The ground over which the shelter [radiation] is located should be typical of the surrounding area. A level, open clearing is desirable so the thermometers are freely ventilated by air flow. Do not install the sensor on a steep slope or in a sheltered hollow unless it is typical of the area or unless data from that type of site are desired. When possible, the shelter should be no closer than four times the height of any obstruction (tree, fence, building, etc.). *The sensor should be at least 100 feet from any paved or concrete surface.*


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## gman19 (Apr 5, 2011)

NYCruze2012 said:


> Is it possible that it is picking up some hot air from the engine?
> 
> Hoping my Cruze and my Droid 3 are still here to send this message barring any engine fires!



If sitting idle...yes, especially if A/C is running expelling even more heat.
Driving down the highway, mine is usually only 2-4 degrees higher than what local reports are on my phone.

Remember, even moving down the highway, the sensor is still picking up heat from the blacktop; it is 
literally "slicing" through and sampling from a layer of superheated air. The temperature will never stabilize to
what a properly measured NOAA reading will be; as indicated in my previous post.

There is a port in the front fascia for the sensor...I haven't looked into this, but how well is the sensor aligned
with that port?? This might explain why some Cruzes are not as far off as others....just a thought.


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## NickD (Dec 10, 2011)

Many such articles like this one regarding do we really have global warming?

UN global warming data skewed by heat from planes and buildings - Telegraph

So why should the Cruze be any different? (With a smile on my face.)

Recently went shopping for a home thermometer, all are made in China, huge display on the shelves, every thermometer read different. Are we moving forwards or backwards?

This is not a photo of the weather stations at any of my airports, but typical, listen to your weather reports, typically taken at your local airport.


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## rbtec (Feb 3, 2012)

Does any one have a picture of where the sensor is located?


Sent from my Autoguide iPhone app


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## 70AARCUDA (Nov 14, 2010)

...it's mounted in the drivers-side bumper fascia (item #14 in below parts illustration), inside the little _*circular recess *_on the lower-left side below the horizontal ridge:

http://parts.nalleygmc.com/images/parts/gm/fullsize/1004081P07-008.JPG










...item #1 here:









...it's read by the Body Control Module (BCM).


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## sndguy (Nov 17, 2011)

70AARCUDA said:


> ...it's mounted in the drivers-side bumper fascia (item #14 in below parts illustration), inside the little _*circular recess *_on the lower-left side below the horizontal ridge:
> 
> http://parts.nalleygmc.com/images/parts/gm/fullsize/1004081P07-008.JPG
> 
> ...


And this is almost perfectly ideal FOR THE APPLICATION. I don't want or need an official weather station on my car, I want to know what the road temp is. That is applicable for this application, if I want to know the ambient air temp I'll use "the google" to access "the internets" and find a feed from a local weather station. Which is of no use to me driving on a borderline icy road. I want to know the road temperature. I seriously don't understand why some are complaining about the sensor. I would rather have an infrared surface temp indicator, like the handheld ones that are widely available and I own, on my car than any air temp reading. But I will settle for what the Cruze provides, to me it's a perfectly acceptable compromise. To each their own, I guess.


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## 70AARCUDA (Nov 14, 2010)

...Outside *Ambient* Temperature (OAT) is rather different than _*road icing *_temperature, which is what GM uses it to detect so the computer(s) can "know" when to turn-on stability control to limit tire-spinning and lockup.

...so, *WHY* does GM prominantly display this temperature on the center display, *IF* it's really intended only for internal computer use? Why link it up there with the A/C system? Answer, because it's _also_ used as a threshhold for A/C operation, even though it's NOT really & truly a valid outside ambient air temperature!


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## NickD (Dec 10, 2011)

Engineer that designed that must have been taking coffee or crack breaks during thermodynamics classes. Thermistor is embedded in plastic with high thermal resistance explaining why the response time is so slow. 

Color of the car doesn't make much difference, all those plates are black, just hand feeling it, that black plate is quite a bit warmer than that shiny white bumper. Especially with the sun beating down on it.

Having an OAT in your land vehicle is not really a requirement, but is in aircraft by the FAA to calculate your take off and landing distance. Just another toy. And if you can't tell the difference between a wet or a glary icy road, may be time to visit your opthamologist. 

See ebay has all kinds of thermometers, hygrometers, just inside, outside, or both. Inside may be nice, but really don't need that, have a wife telling me its either too hot or too cold. Then where would you stick these? And could it be another distraction?

Ha, in my town, don't get caught holding a cell phone, 70 buck fine first offense. Then they want to pass yet another law against texting. Just wonder how you can text without holding your phone.


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## Knucklehead1964 (Jul 18, 2012)

Agree, mine is always at least 5 degrees Higher!


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## NickD (Dec 10, 2011)

Knucklehead1964 said:


> Agree, mine is always at least 5 degrees Higher!


Yeah, but it is compensated for by the fuel used reading low.


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## NickD (Dec 10, 2011)

Dug out my precision pyrometer to learn the dash indication reads exactly the same as the sensor does. So with mine, not a question of sensor inaccuracy. That area was 4*F greater than the ambient air, so as Realtors say, it's location, location, location.

In this case, the sensor is okay, but the location is not in a good area. It will read correctly if the car is parked overnight in a garage where the engine and related components are the same temperature as the ambient air.


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## champcar (Aug 17, 2013)

Nick D

Confucius has said, man who has two watches never knows what time it is!
I suppose it wouldn't be unreasonable to say man who has two thermometers will never know what the temperature is.

Wasn't Confucius Chinese?

To your question of moving backward or forward, I can only say the Chinese apparently believed in Confucius.


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## NickD (Dec 10, 2011)

champcar said:


> Nick D
> 
> Confucius has said, man who has two watches never knows what time it is!
> I suppose it wouldn't be unreasonable to say man who has two thermometers will never know what the temperature is.
> ...



That's we have the NTIS, ha, took me a while to learn this, was the NBS for years. Two watches or thermometers should read exactly the same. 

Confucius also say, woman that fly upsidedown have crack up. Whatever that means.


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## brian v (Dec 25, 2011)

You two are confucius . But not challenged beyond your wits .
Do not go flying upside down Nick !


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## Jim Frye (Mar 16, 2011)

I think I see why Chevy put the OAT sensor inside the driver's side fog light fascia. If it were mounted in the lower grill area, it might get hit by the road debris that takes out the A/C condenser. Also, it wouldn't work very well on the cars that have the grill shutters.


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## brian v (Dec 25, 2011)

Yep that makes perfect since . Where is the OAT sensor on that civic located ?


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## NickD (Dec 10, 2011)

Thought about moving that ambient air temperature sensor when I was installing fog lamps in my Cruze. But only for a half a second. would have to remove the entire front end, make a bracket and install it in the center of the lower grille about three inches from the top where they are normally installed. Plus remake the harness.

Only time I see that error is when the sun is out and reads around 5*F high, can do that math in my head and learn to live with it. Not much an error anyway. Ha, if I really want to know the temperature, just roll down the window and stick my hand out there.

What about adding a rain detector? Don't need that either, can see that by looking out the window.


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## Jim Frye (Mar 16, 2011)

brian v said:


> Yep that makes perfect since . Where is the OAT sensor on that civic located ?


At the top of the lower grill opening on the driver's side. It hangs down from a mounting clip in the air stream. And the readout is adjustable from the steering wheel menu options plus or minus 5 degrees F.


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## CruzeorCurse (Sep 21, 2016)

My Cruze Diesel runs 5 to 30 degrees high. One night driving thru a tunnel it read 103. Ambient was 81 at most. My concern: Does the engine use this value for fuel management or emissions control?


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## josephz2va (Jul 9, 2016)

The air temperature is always higher than reported. It happens to my 2014 Chevy Cruze every startup. September 9 2016, it was 132 degrees upon startup. After one minute of driving, it cools down to 104 degrees or less, but it also depends on the Humidity outside that affects your Outdoor Temperature reading.


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