What You Need To Know About Code P0113

Our diagnostic tools let us know with one little scan what might be going wrong with our engine. When we notice things like gas costing more or strange smells coming from the exhaust that everything in our engine isn’t working right, which is why we use tools like an OBD-II scanner. 

If you recently pulled up a code P0113 and aren’t sure what that means or what to do keep reading. 


This code means Air Temperature (IAT) Sensor Circuit High Input Problem, in the most technical sense. But, in layman’s terms, this code is indicating that in the IAT sensor 1 or its circuit is experiencing some type of issue. 

IAT Sensor

This part of your engine is in charge of informing the computer, or the powertrain control module (PCM), how hot or cool the air going into the engine is. It’s a thermistor, which is a resistance thermometer. It works well in this role because it is sensitive to temperature. 

In this situation, it works better than a regular thermometer because it can change the resistive value in accordance with any changes in the temperature. If the IAT isn’t working correctly then it can cause some serious damage to your engine, especially if it overheats. 

Other indicators that your IAT sensor is having issues follow

Check engine light. Car dashboard in closeup
  • Check engine lines go on
  • Engine runs lean
  • Issues starting the engine

Is It Important?

This issue isn’t dangerous when driving but it can cause a lot of serious damage to your engine if it is left unattended to. Specifically, with P0113, the engine can run lean and that can lead to the following problems. 

Engine Will Cut Out

If you aren’t getting enough fuel to the engine then it will stop working no matter where you are. When this happens its recommended that the driver put the car in neutral and pull to a safe space. As soon as the fuel level is where it should be the engine will start again. If this happens you should check the fuel system. 

Soft Seize

This issue is caused by excessive agitation between the cylinder wall and the pistons. If a dry spot causes the metals to rub together it causes burns on the side of the piston. When the fuel flows back in it will work again but any damage that’s been caused will remain. Eventually, they will stop working. 

Hard Seizure

Four old piston and connecting rod on white background

This is the “soft seize” on steroids. The low fuel flow causes the piston to continually grind against the wall until the crankshaft arm breaks or bends. This is the part that converts the linear motion of the pistons into a rotation, which is essential for operation. 

Other parts of the engine could also break, like the connecting rod. Once this occurs you may have to replace the entire engine. 

These are the primary issues that you would likely experience if you were to not take care of this P0113 code right away.

Getting To The Root Of It

Now that we know the damage that can occur if this code is ignored let’s find out what might be the cause of the P0113. 

  • Damaged or loose IAT sensor
  • Damaged or loose connection wires
  • Issues with the mass air flow sensor if the IAT is integrated in
  • PCM issues that might require a software update

How To Find The Problem

Step One

Mechanic and car repairing in garage

Start the engine and let it run for five to ten minutes. Then compare the air temperature with the temp of the coolant. In a perfect world, the coolant temperature should be slightly higher than the air temperature. If yours isn’t that way then the air temperature could be the issue. 

Step Two

Check the IAT sensor for corrosion on the circuits or if they are loose. 

Step Three

Get the multimeter and measure the resistance of the IAT. To do this you must remove it from the engine. The car manual will tell you where it is. 

Step Four

Heat up the tip of the IAT sensor. If the resistance decreases that means it’s working. If you get an infinite reading or you see no change then it needs to be replaced. 

Step Five

car mechanic at repair work with thermostat

If the P0113 code still appears then you should get help from a professional mechanic

Things To Look Out For

You want to make sure to check for loose or corroded wiring around your IAT sensor before replacing it. The difference in cost between the two is worth and extensive search. Also, the P0098 reports the same issues but with the alternate IAT sensor in your engine. 

How To Fix It

Since there are a myriad of possible sources of this issue there is no one-size-fix-all for the P0113. If there are corroded wires the code might clear when you replace them. Or the fix might be replacing the entire IAT sensor. 

This type of repair typically calls for a professional touch but it can be done if you have the interest and a bit of know-how. There are repair manuals for checking IAT circuits and wires as well as how to replace them. 

Cropped view auto mechanic with mud on hands fixing automobile.

Just remember, be sure to thoroughly check the connections before replacing the whole sensor. You might end up spending more money when it only required a small fix. 

The Cost Of Repair

Because there are so many possible reasons for this code and solutions there is no way to fully tell how much it would cost to repair. Don’t forget to include the labor, which you can either pay for or put in with time.


While the P0113 isn’t an issue that would cause anyone harm, at least not any human. But your engine could suffer severely, especially the longer you let a lean fuel issue go without repair. This code is one of those issues that you can give to a professional or get a manual and learn yourself. It all depends on how much time you want to put in.

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