You start the car on a normal morning and suddenly the orange engine light comes on. The car otherwise runs fine, maybe it starts a bit harder. You connect your scanner and see P0113. No panic: this is almost never an expensive or dangerous fault. It concerns a small temperature sensor, and often the culprit is just a loose connector.
Quick answer: Fault code P0113 means that the signal from the intake air temperature sensor (IAT) is too high. That sensor measures the temperature of the intake air. A too high signal usually points to an interrupted circuit or a sensor reading too warm, causing the computer to incorrectly adjust the mixture. The most common cause is a loose or corroded connector. You can usually keep driving.
What does fault code P0113 mean?
Your engine wants to know how warm or cold the intake air is, because cold air is denser and contains more oxygen. The intake air temperature sensor (IAT) measures that temperature and sends the value to the computer. This way the car determines how much fuel to inject. With P0113, the computer sees a too high signal from that sensor, which usually indicates an open circuit or a sensor that reports too high a temperature.
Severity: green to orange. It is a mild fault. Often you only notice the light. Sometimes the car starts a bit less smoothly or consumes a fraction more. You can drive safely, but fix it in time because the light stays on and you won’t pass the MOT.
Symptoms
Engine light on. Usually the only thing you notice. The car otherwise drives normally.
Harder starting. Sometimes the car starts a bit more difficult with a cold or warm engine because the mixture is incorrect.
Slightly higher consumption. Because the computer calculates with an incorrect air temperature, consumption can increase slightly.
Possible causes (from cheap to expensive)
Loose or corroded connector (€0 to €20). By far the number 1 cause. A plug that does not make good contact or turns green gives a wrong signal.
Defective IAT sensor (€10 to €40). The sensor itself is worn out or no longer reads correctly. A relatively inexpensive part.
Broken or damaged wiring (€10 to €60). A break or worn wire leading to the sensor causes an open circuit.
IAT integrated in the MAF (€60 to €150). In many cars, the IAT is inside the mass air flow sensor. Then you replace both together.
Step-by-step: how to find the cause yourself
- Read the IAT value live. Connect a scanner and view the live data of the intake air temperature.
- Compare with the outside temperature. When the engine is cold, the IAT value should be roughly equal to the outside temperature. If it deviates significantly, something is wrong.
- Compare with the coolant temperature. Also read the coolant temperature at a cold start. These two should be almost the same.
- Check the connector. Unplug the connector and look for dirt, corrosion, or loose pins. Clean it and snap it firmly back in place.
- Measure the sensor resistance. Measure the sensor’s resistance with a multimeter and compare it to the value from the workshop data.
- Replace the sensor and clear the code. If the sensor is broken, replace it and clear P0113. If the code doesn’t return, that was the cause.
How much does it cost?
Yourself: clean the connector. €0 to €20. The cheapest and most common solution.
Yourself: new IAT sensor. €10 to €40 for parts. Often replaceable with just a few steps.
Garage: diagnosis and repair. €60 to €200, especially if the IAT is inside the MAF or the wiring needs repair.
Fix it yourself or go to the garage?
Cleaning the connector and replacing a separate IAT sensor is something you can easily do yourself, even without experience. If it’s a combined MAF sensor or an invisible wire break, then a multimeter and a bit more patience are needed, or a visit to the garage. The great thing about P0113 is that you start with just a few euros and only scale up if it’s really necessary.
The right tool for this code
For P0113 you want two things: to read and clear the code, and to see the live data from the sensors side by side. These three fit that. Start cheap; use a more advanced tool only if you want to measure deeper or control more functions.
View the Topdon CarPal →
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View the Launch CRP919X →Related fault codes
P0113 belongs to a family of codes related to intake air temperature. If you encounter one of these, the approach is similar: P0112 (signal too low instead of too high), P0111 (sensor range or performance), and P0102 (often the combined MAF/IAT sensor). If you don’t yet know how to read and clear codes, first read reading and clearing fault codes.
Frequently Asked Questions
Can I keep driving with P0113?
Yes. It’s a mild sensor code, not an acute engine problem. However, the light stays on, the car may start a bit less smoothly, and you won’t pass the MOT with it.
What exactly does the IAT sensor do?
The intake air temperature sensor measures the temperature of the air being drawn in. The computer uses that value to inject the correct amount of fuel.
How do I check the IAT value myself?
Read the live data with a scanner. With a cold engine, the IAT should be roughly equal to the outside temperature and the coolant temperature.
Will I fail the MOT with P0113?
A lit engine warning light is a fail point. So fix the code before you go for inspection.
In summary
• P0113 = a too high signal from the intake air temperature sensor (IAT).
• Always start with the connector; a loose or corroded plug is the number one cause.
• If that doesn’t solve it: measure the sensor, check the wiring, replace the sensor.
• You can drive safely, but you won’t pass the MOT with the warning light on.