2016 Outside Temperature Wrong...

[mikeyk101]

So my 2016 Crew Cab with the Mylink displays the outside temperature. A couple days ago I noticed when I started up truck, it displayed the outside temperature as 60 degrees. The actual outside temp was just a little warmer than that. Later in the day, it was considerably warmer but the display still showed 60 degrees. Yesterday, again when I started the truck, it again showed 60 degrees when I know it was warmer. Later in the day, I know the outside Temps were around 85 degrees but the most that the display showed was 63 degrees.

 

Does anyone know why the Mylink temp display would be off by that much? I will probably be bringing it to dealer soon anyway for last free oil change an it is still under warrantee. I was just curious about a possible cause to this problem. Thanks

[aseibel]

Is the temp sensor caked in mud or something? That would be my first guess. Its just inside the grille on the upper passenger side. Strapped to one of the braces behind the grille.

 

If its clean, then it could just be shot.

 

Mine reads funny when I have the snow plow on. If your airflow is blocked to that area, that could also affect it. do you have anything mounted to the front of your grille?

[newdude]

I could think of a few more important things to worry about (like driving and the road ahead of you) but...

 

#PIT5232C: Diagnostic Tip - Outside Temperature Will Not Update Or Inaccurate - (Oct 10, 2016)

 

The following diagnosis might be helpful if the vehicle exhibits the symptom(s) described in this PI.

Condition/Concern

Some owners may comment of any of the following issues:

• The outside temperature display is inaccurate and will not update.
• The outside temperature display takes too long to update.
• The outside temperature display shows 32° F (0° C). This concern may have started after disconnecting the battery or reprogramming a module.

Recommendation/Instructions

The ambient temperature uses an algorithm that delays updating the display until certain conditions are met. This ensures that the sensor does not detect engine or road heat when the vehicle is idling/slow speed driving.

 

The outside temperature will begin to update if driven above 20 mph for at least 5 minutes. If the vehicle speed drops below 20 mph, the timer will reset and the display will stop updating. Once the display starts to update, it may take several more minutes of driving above 20 mph for the display to fully update.

 

Additionally, if the vehicle sits for at least 8 hours, the display will be updated when the ignition is turned on.

 

Please follow this diagnostic or repair process thoroughly and complete each step. If the condition exhibited is resolved without completing every step, the remaining steps do not need to be performed.

 

Additional SI Keywords

Ambient, Not, Accurate, Inaccurate

 

 

[aseibel]

I could think of a few more important things to worry about (like driving and the road ahead of you) but...

 

yeah, the number on the screen really isn't that important. But, unfortunaltely, our truck's smart HVAC system performance is tied to the outside temp. If the sensor is malfunctioning it will render the AC useless. That makes it harder to concentrate on the road in the summer.

 

Turning on the AC to LOW won't blow any cold air out if the truck thinks its already 60 degrees. I learned this when my truck wouldn't blow any hot air, even when I turned the thermostat up to HI. When my snow plow blocks the air flow and I'm driving slow, the truck thinks its 100 degrees outside and won't blow any heat.

[MaverickZ71]

My '09 Silverado does that too. It is stupidly programmed into the system that way from the factory.

 

Here is GM's official explanation:

 

The outside air temperature display utilizes a very specific filtering routine of the Ambient Temperature Sensor signal so the display will update gradually without making large jumps in the reading. This is designed to eliminate the possibility of erratic readings under certain driving conditions.

The temperature display is always allowed to update quickly when the ambient temperature is getting colder while driving, but the display takes much longer to update when the temperature is getting warmer. This prevents false updates to the temperature display while driving in slow or stop-and-go traffic in hot weather.

The temperature display will always read the actual ambient temperature when the vehicle is started if the temperature has dropped since the last key cycle. It will not immediately update to the actual ambient temperature if it has gotten warmer since the last key cycle unless the ignition has been off for at least 2.5 hours.

 

So it will always update when it gets cooler, but may hardly ever update when it gets hotter.

 

I don't know why the General can't program their temp sensors to display an instant value like other manufacturers seem to be able to do. On mine, this time of year, a lot of the time around town it will be stuck on 60 degrees (or whatever the morning startup temp was) when it's 80+ out later in the day. And sometimes in the winter it will be stuck on 30 degrees when it has warmed up to 50+. This affects the operation of the HVAC system's Auto mode for the AC. I don't know if this will work on yours, but on the GMT900's (2007-2013 models), if you press the Recirc and AC buttons on the HVAC head unit at the same time, it will do an instant update for the actual temperature of the underhood temp sensor. Then you'll probably have to push your Auto button or AC button again on the HVAC to turn your AC back on again. Hope this helps.

[mikeyk101]

Is the temp sensor caked in mud or something? That would be my first guess. Its just inside the grille on the upper passenger side. Strapped to one of the braces behind the grille.

 

If its clean, then it could just be shot.

 

Mine reads funny when I have the snow plow on. If your airflow is blocked to that area, that could also affect it. do you have anything mounted to the front of your grille?

 

I will check on this. No, nothing is mounted to the grille. You may be right on the blockage and that will be next step.

 

As far as the temp gradually rising, I can understand that as well. However when I first noticed it doing this, I had been driving at highway speeds for over 30 miles. This was also steady without stop and go traffic. I figure that should have been plenty of time for it to update.

 

And I did not know that the AC was tied into the temp sensor. That is good to know.