#OBD Codes
P0113 – Intake air temperature sensor 1 circuit high input
Technical definition
Intake air temperature sensor 1 bank 1 circuit high
What does P0113 mean?
The P0113 trouble code indicates your car is having trouble measuring the temperature of the air coming into the engine. Specifically, it means the intake air temperature (IAT) sensor is reading a voltage that's way too high, nearly five volts, which is equivalent to -40°C/-40°F.
This sensor typically sits within the mass air flow (MAF) sensor, the manifold absolute pressure (MAP) sensor, the intake manifold, or somewhere along the air intake path between the air filter and the throttle body.
IAT sensor in engine bay
Its job is simple but crucial: provide accurate air temperature readings to the car's engine control unit (ECU) or powertrain control module (PCM). These modules act as your car's brain, taking full control of engine operation.
Why is the intake air temperature important?
Engines rely on precise air-fuel ratios, and air temperature is a big part of the equation. Cold air is denser and contains more oxygen, so your car needs more fuel for combustion. On the flip side, warm air requires less fuel. The IAT sensor measures the temperature of the air entering the engine and helps the ECU maintain this delicate balance for optimal performance, fuel efficiency, and reduced emissions.
The sensor operates using a thermistor – a component that measures temperature by changing its resistance. Its resistance decreases as the air temperature rises. Lower resistance results in lower voltage output and vice versa. If the car's powertrain control module detects an abnormal voltage (above 4.7 volts), it flags the reading as unrealistic and triggers a check engine light with a P0113 diagnostic trouble code.
Example: If it’s 30°C/86°F outside but the IAT sensor claims it’s -40°C/-40°F, your engine might overcompensate by injecting too much fuel, which can lead to poor fuel economy or reduced engine power.
How serious is P0113?
In most cases, the P0113 code isn’t an emergency and won't leave you stranded, but it’s still not something to ignore. If the problem worsens, you could experience engine misfires, which occur when the air-fuel mixture doesn't fully combust, leading to costly repairs.
Fortunately, in most modern vehicles, a faulty IAT sensor typically causes no noticeable symptoms beyond turning on the check engine light. This is because engine management systems use backup strategies to keep the engine running smoothly even when sensors fail.
Example: If an IAT sensor fails on a 2000 Dodge truck, the ECU ignores the faulty sensor readings and uses a default value of 38°C/101°F instead of the unrealistic -40°C/-40°F.
This is usually enough for the engine to operate without immediate or severe damage.
Can I still drive with P0113?
Yes, you can. But it’s best to fix it soon.
Driving without accurate temperature readings can lead to higher fuel consumption, cold start issues, and potential long-term damage.
Common symptoms of P0113
Symptoms associated with the P0113 code include:
- Check engine light is on
- Difficulties to start in cold weather
- Misfiring
- Poor fuel economy
- Poor acceleration
Common causes of P0113
P0113 appears due to:
- Faulty IAT sensor: The most common culprit
- Wiring issues: Broken, shorted, or corroded wires
- Connector problems: Damaged, corroded, or moisture-filled connectors
- Dirty air filter: Restricts airflow and disrupts sensor readings
How to troubleshoot P0113
Use these tips to diagnose and fix a P0113 error code accurately:
Scan fault codes
Start by using an OBD scan tool to look for any other related trouble codes, which may provide additional clues to the underlying problem and its severity. These faults include:
- P0100-P0104: These codes are associated with the mass air flow sensor issues. Since the IAT sensor is usually integrated into the MAF, they might indicate common issues, such as loose or corroded connectors or faulty wiring.
- P0110: Indicates a fault in the IAT sensor circuit, which may suggest an open or short circuit. This could be due to a wiring issue or a malfunctioning sensor.
- P0171 or P0172: This indicates a wrong air-fuel mixture, meaning there is too much (lean) or too little (rich) air. These fault codes inform you about the higher severity of P0113, meaning you can't ignore it.
- P0300-P0312: These codes indicate cylinder misfires. They are quite rare in conjunction with P0113, but they can signal very high severity of the P0113 issue.
Clear the codes and test drive
Use your scan tool to clear the fault codes.
- If the fault codes immediately reappear: This indicates the issue is ongoing. Skip the test drive and continue troubleshooting other potential causes.
- If the codes clear successfully: Drive your car for about 15 minutes to fully warm up the engine and observe its behavior.
After the test drive, perform another scan to see if the code reappears. If it does, this confirms the problem persists and requires further investigation.
Analyze intake air temperature live data readings
Live data tools, such as OBDeleven, enable you to monitor real-time intake air temperature readings for Volkswagen Group vehicles. To access these values in the OBDeleven VAG app, connect to the vehicle and navigate to the control unit list. Under the "Live data" tab in the engine control section, you will find the air temperature readings:
OBDeleven live data feature
Normally, the intake air temperature should be similar to or higher than the outside air temperature. If it is significantly lower, it confirms that the issue is still ongoing.
Some vehicle models may display a fallback temperature value if the sensor fails instead of -40 degrees.
Further reading: How to read OBD live data
Inspect the IAT sensor and its wiring
Look for physical damage, corrosion, or disconnections in the IAT sensor and its wiring. Also, check the air filter for excessive dirt or debris.
Test the air intake temperature sensor with a multimeter
To check the operation of the AIT sensor, you will need a multimeter and a hair dryer. Follow these steps:
- Remove the IAT sensor
- Set the multimeter to measure resistance (Ω)
- Connect the multimeter to the sensor terminals
- Use a hair dryer to blow hot air onto the sensor while observing changes in its resistance
Under normal conditions, the sensor's resistance should decrease as it warms up. However, if the resistance remains unchanged as the temperature increases, this indicates that the sensor is faulty and needs replacement.
Note: This video provides a more informative guide on testing the AIT sensor.
How much does it cost to fix a P0113 code?
Fixing this issue is often inexpensive. A standalone IAT sensor can cost around $10-$30 for the part. However, if it’s integrated with the MAF sensor, you may need to replace the entire unit, which starts at $30. Labor is minimal – just a couple of screws and a connector.
Disclaimer: Advice, how-to guides, and car care tips on our blog are intended as helpful resources for general maintenance and repairs. While we strive for accuracy, the information is provided to the best of our knowledge and should be used at your own discretion and risk.
Always refer to your vehicle's owner's manual or consult a certified mechanic for specific repair details and safety procedures.
Always refer to your vehicle's owner's manual or consult a certified mechanic for specific repair details and safety procedures.