OBD-II Car P0113 Error
What it means
P0113 means 'Intake Air Temperature (IAT) Sensor 1 Circuit High Input'. The IAT sensor measures the temperature of air entering the engine so the ECM can calculate air density and trim the fuel mixture. The IAT is a thermistor: cold air = high resistance, hot air = low resistance. P0113 sets when the ECM sees an abnormally high voltage (which it reads as an impossibly cold reading, like -40°F), usually from an open circuit or a disconnected sensor. Common symptoms: check engine light, possible hard starting, rough idle, slightly reduced fuel economy or performance — though many cars run almost normally because the ECM substitutes a default value.
Common causes of the P0113 error
- Disconnected or loose IAT sensor connector
- Open circuit or broken/corroded wiring in the IAT signal or ground wire
- Faulty IAT sensor (open internally)
- On vehicles where the IAT is built into the mass air flow (MAF) sensor, a failed MAF unit
- Corroded connector pins or poor ground; rarely, an ECM fault
How to fix the OBD-II Car P0113 error
- 1Locate and reseat the IAT sensorFind the IAT sensor — it's in the air intake duct, air filter housing, or built into the MAF sensor. Unplug the connector, check for a loose fit or backed-out pins, then firmly reconnect it. Clear the code and see if it returns.
- 2Inspect the wiring and connectorLook for chafed, melted, or broken wires and corrosion in the connector. Because P0113 is a 'high input' (open-circuit) code, a broken signal wire or bad connection is the usual culprit. Repair any damage found.
- 3Test the sensorWith a multimeter, measure the sensor's resistance and compare against the temperature-vs-resistance chart in the service data. Resistance should fall as the sensor warms. An open (infinite resistance) reading means the sensor is bad.
- 4Replace the sensor (or MAF)If the IAT tests bad, replace it. On many vehicles the IAT is integral to the MAF sensor, so the whole MAF unit is replaced. Use a quality part and reset the code.
🧰 When to call a professional
This is usually a DIY-friendly fix. Call a professional if the wiring damage is buried in a harness, if the code persists after a new sensor (possible ECM or ground issue), or if you're not comfortable using a multimeter to test the circuit.
OBD-II P0113 error — FAQ
Is it safe to drive with this code?
Generally yes. P0113 alone rarely causes serious drivability problems because the ECM falls back to a default intake temperature value. You may notice slightly worse fuel economy or cold-start behavior. It's safe to drive while you arrange the repair, but don't ignore it long-term.
How much does it cost to fix?
Often very cheap. A standalone IAT sensor is typically $10–$50 and easy to swap yourself. If it's part of the MAF sensor, the part can run $80–$300. Shop labor is usually minimal (around $40–$100) since the sensor is easy to reach.
What's the difference between P0113 and P0112?
Both are IAT circuit codes. P0113 is 'high input' — the ECM sees high voltage, reading air as unrealistically cold, usually from an open circuit or disconnected sensor. P0112 is 'low input' — low voltage, reading air as unrealistically hot, usually from a short to ground.
Sources
This guide is independently written and not affiliated with OBD-II. Always unplug appliances before servicing and follow your model's manual. Error codes and steps can vary by model — when in doubt, consult a qualified technician.