P0113 Code: Intake Air Temperature Sensor Circuit High – Causes and Fixes
Quick answer: P0113 means the intake air temperature (IAT) sensor signal is reading high voltage, which the computer reads as very cold air. It is usually an unplugged or damaged connector, broken wiring or a failed sensor. On many cars the IAT sensor is built into the MAF sensor.
What P0113 means
The IAT sensor measures the temperature of air entering the engine. Its resistance changes with temperature. A "circuit high" code means the voltage is near the top of its range, which usually means an open circuit: a disconnected plug, broken wire or failed sensor.
Symptoms
- Check engine light.
- Usually little change in driving.
- Sometimes hard starting or rough running, especially in extreme temperatures.
Common causes
- An unplugged or loose IAT or MAF connector, often after an air filter change.
- A broken wire or corroded connector.
- A failed IAT sensor (or MAF sensor with built-in IAT).
- A fault in the sensor ground circuit.
Before you replace parts
- Read the codes with an OBD-II scanner and write down every code, not just this one. Several codes together often point to one cause.
- Look at the freeze frame data: engine temperature, speed and load when the code set.
- Check for technical service bulletins (TSBs) for your vehicle; some codes have known fixes or software updates.
- Clear the code and drive. If it returns quickly, the fault is current; if it takes days, it may be intermittent.
How to diagnose it
- Check the connector is fully plugged in, especially if the air filter was just changed.
- With a scan tool, compare the IAT reading with outside air temperature on a cold engine. A reading of around -40 is a typical sign of an open circuit.
- Check wiring and measure sensor resistance against the service manual.
How to fix it
- Reconnect or repair the connector and wiring.
- Replace the IAT sensor, or the MAF sensor if the IAT is built in.
Related codes
About this guide
Code definitions here are the generic OBD-II meanings. Manufacturers can add their own details, and the same code can have different common causes on different engines, so use a service manual or a qualified technician for a full diagnosis. Parts named are ones we list; check the vehicle, engine and part number in each listing, or send us your year, make, model and engine and we will check before you order.
Questions
Can I drive with P0113?
Usually yes, but get it fixed. The computer uses the IAT reading to adjust fuel and timing.
Why did P0113 appear after an air filter change?
The IAT or MAF connector is often unplugged or disturbed when the airbox is opened. Check it is fully clicked in.
Where is the IAT sensor?
In the air intake, often in the airbox or built into the MAF sensor.
What does circuit high mean?
The signal voltage is near its maximum, which usually points to an open circuit or failed sensor.
Is P0113 the same as P0112?
No. P0112 is IAT circuit low, usually a short; P0113 is circuit high, usually an open.
