What it means
The IAT signal voltage is above threshold, which the ECU interprets as an implausibly cold intake (open-circuit-like behaviour). Usually open wiring or a sensor that has failed open.
At a glance
- Usually lights the check-engine light
- Affects emissions; the car can fail an emissions test
How it works
Intake air temperature sensor 1 reports the temperature of air entering the engine so the ECU can adjust fueling and ignition. P0113 sets when its circuit voltage is too high, which typically indicates an open circuit and is interpreted as unusually cold intake air.
Common causes
Most likely first.
- Open circuit in sensor or wiring
- Corroded sensor connector
Symptoms
- Check engine light on
- Hard starting or rough running
- Reduced fuel economy
How to diagnose it
- Record freeze-frame data and compare live IAT sensor 1 temperature with ambient temperature after a cold soak; an implausibly cold reading points toward an open signal circuit.
- Inspect the IAT sensor 1 connector and harness for unplugged terminals, corrosion, broken wires, or damage.
- Check whether the sensor is integrated into the MAF assembly on this vehicle, and inspect that assembly's connector if applicable.
- Test the sensor and signal circuit for an open or poor connection using the wiring information and manufacturer's specification.
- If wiring is sound, test or substitute the sensor only as directed by the vehicle's diagnostic procedure, then confirm the live reading responds plausibly.
Common fixes
- Reconnect or clean the IAT sensor 1 connector.
- Repair an open or damaged IAT signal wire.
- Replace a sensor that fails the specified resistance or signal test.
- Replace the MAF assembly only if IAT sensor 1 is integrated and the assembly is confirmed faulty.
Can I keep driving?
A short trip is usually possible if the engine runs normally, but avoid demanding acceleration until the fault is diagnosed. The ECU may miscalculate fueling from the falsely cold reading, increasing fuel use or causing rough starting and running.
A code shows where the control module detected a fault, not always which part failed. Check the causes in order and confirm with a test before replacing parts. Have several codes? Check them together
This is a generic code: it means the same on every make. The car’s maker may add more detail in its own service information.