[SilverCruzer]

Not a deal breaker by any means, but has anyone else noticed the outside themometer being off? From what I noticed, it seems off by about 3-5 degrees.
I am aware of the service bulletin regarding the time delay of udate after frist starting the car, but I noticed its still off when driving for some time. For example, on my way home from work it stated 33 degrees as I pulled into the driveway. My house oustide digital themometer (in the shade) stated 28 degrees.
Again, not that big of a deal, but my previous older cars were more accuarate, and when the season (now) is quite often right around the freezing point, a few degrees says a lot.

 

[Inline4_driver]

There's a lot of factor that could be affecting this. All my cars that had outside temp sensors would always be off by a couple degrees. Depending on where they positioned the engine heat could be affecting it. Also the head wind could be affecting it too. I wouldn't trust any one of them to be accurate plus all you need to do to properly gauge the temp is open the window and check very quickly with your hand.

 

[Sour Kruat's 951]

I also had this problem with mine.

I installed the foglights so I had to disconnect the battery. After the battery was re-connected and everything was reprogrammed in the car it started the outside temp, among other things, started to work much better. This is a YMMV since I have not heard of anyone else doing a battery reset yet.

The service manual did not mention this, but it does mention several of the items that need to be reprogrammed after a battery disconnect. Like the auto windows and such.

Nothing directly pointed to the temp reading but this was my experience.

 

[racer114]

I have four of these thermometers in my vehicles and they are all off. The worst is the Chrysler product, it is off typically by 5-8 degrees. The Fords are close, +/- 1 degree and the Cruze is 3-4 degrees optimistically high.

 

[cruze-control]

...with the "funky" way they (Chevy) have the computer read & display the thermometer sensor values (speed dependant?...WTF?), I, too, doubt the accuracy of what I see.

...however, since I do have a couple spare remote TEMP / HUMIDITY sensors in the garage for our home weather station. I think that I can tape one adjacent to the car's thermistor sensor and record the results. Since this remote sensor is calibrated at ±1°F, I should be able to get a meaningful answer.

wow! i didnt know it was speed dependent. why would they do that though? to compensate for the wind chill factor??

 

[SilverCruzer]

wow! i didnt know it was speed dependent. why would they do that though? to compensate for the wind chill factor??

I believe the reason for this is the faster you drive, the quicker the air gets displaced around the sensor. Say for example, your car has been sitting in a 45 degree garage. You then pull out and drive around your 'hood at 15 mph, the outside colder air is going to take a while to "flush" the warmer garage air away from the sensor. If you jump right on the interstate however, faster air will flush the warmer air away faster.
It's my best guess.

 

[cruze-control]

both explanations sound good to me. lol. one of my cars doesnt have that feature. when im parked indoors and drive outside it will display around 25-30 degrees celsius for the first few minutes then it will slowly go down to the proper temp which is around 1-5 degrees celsius.

 

[ALiCE]

EUROPEAN CRUZE
In my user manual it states:
"Temperature drop is indicated instantly and the rise of the temperature is indicated with a SHORT delay".

The problem with the temperature display began after a software update to address another problem, the "transport mode".

Now, here comes my opinion, the above were certain facts:
Anyway, because they couldn't solve it after a year (!!!!!!) they issued the update about how the temperature is updated - trying to transform it into "it's not a bug, it's a feature".

Now, the temperature display is not such a big problem BUT the automatic climate control depends on that too, among other things. So an inaccurate display of the outside temperature translates into an inaccurate setting of the in-car temperature.

Because I pursued them to fix the temperature display, they did it to my car! They changed the BCM, did a software update and (at least for now) the temperature is shown corectly.

 

[ALiCE]

It may be a way of solving it, if it really doesn't work as it should.
If the outside temperature drops during a trip, but the temp displayed doesn't (check with a termomether), then yes, it is defective.

 

[montgom626]

EUROPEAN CRUZE


Now, the temperature display is not such a big problem BUT the automatic climate control depends on that too, among other things. So an inaccurate display of the outside temperature translates into an inaccurate setting of the in-car temperature.

My AUDI A8L is off by 2-3 degrees. Who cares? Why care? If you need the temp gauge to tell you if you are "comfortable" in your car, then you have bigger issues that the gauge. If 75 makes you happy, select 75. If 79 makes you happy then select 79.

 

[ALiCE]

I PAID for a WORKING AUTOMATIC climate control.
Normaly, I should set it to about 23 degrees and forget it.

It's not about a constant difference 2 or 3 degrees.
If outside were 30+ C and the display showed 14C, with the temperature set to 21C, i were sweating!

 

[montgom626]

It's not about a constant difference 2 or 3 degrees.
If outside were 30+ C and the display showed 14C, with the temperature set to 21C, i were sweating!

I am not so sure that the outside temp controls the inside temp
I always imagined the outside thermometer measured the outside and did not influence the temp control for the interior.

I have never done it, but can't I set the temp to 85 F for the interior when the exterior is 30 F and also when the exterior if 100F?

How does the thermometer for the exterior influence the setting for the interior and/or the output of the heater or A/C?

Anyone know the answer?

 

[ALiCE]

If you set the interior temp for 85F, when the outside is 30F, it should blow hot air inside.
If you set the interior temp for 85F, when the outside is 100F, it should blow cold air inside.

BUT if you set the interior temp for 85F, when the outside is 100F, and the read temperature (displayed on the dashboard) is 30F, it will be messed up and it may blow hot air inside.

 

[montgom626]

If you set the interior temp for 85F, when the outside is 30F, it should blow hot air inside.
If you set the interior temp for 85F, when the outside is 100F, it should blow cold air inside.

.

You are right. My 2LT allows me to turn off the A/C . If it is 80F outside and I set my temp to 85F I will get 85F from my heater (call me crazy). Now, if I set my interior temp (no A/C) at 55F, I will get a warm 80F blowing into my face and sweaty armpits

My question is, does anyone know if the external temp gauge has any influence on what my interior car thermostat does????? I can't see how it does or why it would even try. I always assume that the interior temp gauge controls my interior temperature. And that the exterior temp gauge just passively reports the exterior temperature to some digital gauge on the dash. If I set my interior temp to 70F, and it is 10F outside and 10F inside the car (before the car starts) then my heater will pump out heat until it hits 70F in the inside of the car raising the interior temp from 10F to 70F (up 60F) and then slow down, only providing heat to the interior when the interior temp drops below 70F. The car heater does not "know" and does not "care" what the outside temp is. It only responds to the interior temperature. The exterior temp gauge doe not report the exterior temp to the interior temp control at all. Why would it?

HELP

 

[TSURacing]

It may use it to determine when to use recirculate and when to blow outside air in.. No data on that, just a guess.

 

[wolfpack86]

Here is my guess.

There is no sensor on the car specific to the outside temperature. Instead they use the reading from the MAF, as this would be free. The MAF is located directly above your engine which means it can become "heat soaked". Therefore the vehicle has no way of knowing the actual temperature until the vehicle is moving and air can flow throw the intake and cool the MAF to the ambient temp. The only way to fix the issue would be to install a temp sensor far away from the engine, and lets face it for a <$20,000 car no car company is going to do that.

 

[ChevyMgr]

Here's how it really works.

In automatic operation, the HVAC control module maintains the comfort level inside of the vehicle by controlling the A/C compressor clutch, the blower motor, the air temperature actuators, mode actuator and recirculation actuator.


To put the HVAC system in automatic mode, the following is required:

1. The auto switch must be activated.
2. The air temperature switch must be in any other position than full hot or full cold position.

Once the desired temperature is reached, the blower motor, mode, recirculation and temperature actuators automatically adjust to maintain the temperature selected. The HVAC control module performs the following functions to maintain the desired air temperature:

• Monitors the following sensors:
- Ambient air temperature sensor
- Lower left air temperature sensor
- Lower right air temperature sensor
- Upper left air temperature sensor
- Upper right air temperature sensor
- Windshield temperature and inside moisture sensor
- Ambient light/sunload sensor
- Air quality sensor
• Regulate blower motor speed
• Position the air temperature actuator
• Position the mode actuator
• Position the recirculation actuator
• Request A/C operation​

When the warmest position is selected in automatic operation the blower speed will increase gradually until the vehicle reaches normal operating temperature. When normal operating temperature is reached the blower stays on high speed and the air temperature actuators stays in the full heat position.

When the coldest position is selected in automatic operation the blower stays on high and the air temperature actuators stay in full cold position. The mode actuator remains in the panel position and the recirculation actuator will remain in the recirculation position.

Under cold ambient temperatures, the automatic HVAC system provides heat in the most efficient manner. The operator can select an extreme temperature setting but the system will not warm the vehicle any faster. Under warm ambient temperatures, the automatic HVAC system also provides air conditioning in the most efficient manner. Selecting an extreme cool temperature will not cool the vehicle any faster.
The HVAC control module evaluates the information of the air quality sensor and closes the recirculation flap while the air quality sensor switch is pressed, as soon as the concentration of pollutants exceeds a predefined value.

In automatic mode the values of the windshield temperature and inside moisture sensor are used as control inputs for the HVAC control module application to calculate the fog risk on the passenger compartment side of the windshield and ability to reduce fuel consumption by decreasing A/C compressor power to a minimum without causing any fog. The A/C compressor and the defrost mode are activated to prevent or remove fog on the passenger compartment side of the windshield. The sensor will also enable partial recirculation mode in order to improve heat-up performance of the passenger compartment under cold ambient temperature conditions without the risk of mist build-up on the windshield.

 

[ALiCE]

a) There IS a temperature sensor, located in the front bumber, in the left side of the car, in the fog light space.
b) The MAF usually can't have a temperature close to the outside temperature (because of the turbocharger, intercooler, etc). Also, the temperature is about the same, with the engine started, regardless if the car is moving or not.
c) GM Romania told me that "automatic climate control" is using the outside temperature, among other things like sun load, light, air quality, etc.

 

[ChevyMgr]

The outside temperature sensors only function is to display the outside temperature. It has no effect on the Auto A/C.

edit: I'm wrong, it does figure into the settings. Most GM vehicles have a sensor inside for this, usually in the headliner, but the service manuals says the Cruze uses the outside sensor.

 

[wolfpack86]

a) There IS a temperature sensor, located in the front bumber, in the left side of the car, in the fog light space.
b) The MAF usually can't have a temperature close to the outside temperature (because of the turbocharger, intercooler, etc). Also, the temperature is about the same, with the engine started, regardless if the car is moving or not.
c) GM Romania told me that "automatic climate control" is using the outside temperature, among other things like sun load, light, air quality, etc.

I was thinking of the non-turbo Cruze. Even on the 1.4L TC there is still a sensor after the air filter box, i believe is temp (which would mean the CAC and turbo have no bearing on the temperature).
I am not real familiar with GM's sensors but I do know I have seem many airflow sensors get heat soaked under the hood.
I had read that sensor on the bumper (fog light area) was to turn the automatic lights on and off. If you care to check just unplug it and see if the lights or the temp are affected.

Any GM guys that can confirm this sensor is indeed for the outside temp?