Outside Air Temp 5 deg hi

My outside air temp is always 5 deg higher than smartphone weather app. Phone agrees with TV weather. Is there any way to calibrate it down? Does fuel injection system use this temp as input for mass air flow calc?

 

My front yard thermometer reads different then my back yard thermometer. Best way to test is get an infrared thermometer and shoot near the sensor on the truck.

 

Do you know where sensor is located on truck?

 

Absorbed heat from radiator is my guess.

 

Sorry no I don't. But I would trust almost any thermometer in my presence before I trust an app that is reading from a weather station that could be miles away which is why I would check it on the truck.

 

Understood. I agree on App. It's just the radio and TV weather broadcasts agree. I will measure near truck

 

There is a good chance they both get their readings from the same source.

 

Have you looked at yours and is it in agreement with other indications or local (at truck) measurements? I guess as long as it trends properly, no big deal. Just wondered IF was input to fuel injection system? Truck runs fine and mileage good. Prob not issue. Will measure at truck today

 

Upon start up during any warm months when the truck is sitting it will always be higher. Could be as much as 20 or more depending on several factors. Heat gets radiated off of the blacktop, and plastic/metal of the vehicle. Once you start moving it'll pick up the ambient air temp and should be pretty accurate. The sensor is normally behind the grill somewhere usually in front of the radiator, but it varies on every vehicle due to design.

 

My dealer read a tech bulletin from Toyota that states the outside air temp may be up to 4 deg uncertainty and anything w/in that is normal. Not a recall just a response if asked. I guess others have wondered. He said that sensor does not feed fuel injection

 

I work for another import car dealer as a tech. If these are anything like ours then they will be off a few degrees. Like others have stated they can be way off at startup. They have "saved" the previous temp from the last drive cycle. These sensors are located at the front of the car. They usually require some sort of movement before they read a temp. Road temps usually effect the accuracy along with other variables. They are simply a sensor and not some calibrated thermo terms. They will have a computer the digests the signal and then apply some algorithm to display a temp. They do NOT feed into the ecu. The truck will have a sensors built into the intake system of the car to have a exact temp reading of the air going into the car. These are usually exactly to within a tenth of a degree. There should be a way to adjust them, at least there is in the line I work on. Hope this helps.