What it means
The ECU detects a general electrical fault in the intake air temperature (IAT) sensor circuit. Signal absent, shorted or out of plausible range. Generic catch-all when no more specific IAT code (low/high/range) is set.
At a glance
- Usually lights the check-engine light
- Affects emissions; the car can fail an emissions test
How it works
The intake air temperature sensor measures the temperature of air entering the engine so the ECU can account for air density when managing fueling. The ECU monitors the IAT circuit and sets P0110 for a general electrical or plausibility fault, such as a missing or shorted signal, rather than identifying a specific low or high condition.
Common causes
Most likely first.
- IAT sensor failed (open or shorted)
- IAT wiring or connector fault
- Combined MAF/IAT module faulty
Symptoms
- Check engine light on
- Hard starting, especially when cold
- Rough idle or hesitation
- Reduced fuel economy
How to diagnose it
- Review freeze-frame data and compare the IAT reading with ambient temperature when the engine is cold to identify an implausible or missing signal.
- Inspect the IAT sensor connector and wiring for loose terminals, corrosion, broken wires, or signs of a short.
- If the IAT is integrated into the MAF assembly, inspect that shared connector and check whether other airflow sensor faults are present.
- Use live data during cold start and warm-up to see whether the IAT reading changes plausibly rather than staying fixed or dropping out.
- Test the IAT sensor and its circuit against the manufacturer's specification to distinguish a sensor failure from a wiring or connector fault.
Common fixes
- Reconnect the IAT connector and secure the wiring.
- Repair damaged IAT circuit wiring or corroded terminals.
- Replace a failed standalone IAT sensor.
- Replace the combined MAF/IAT assembly only if testing confirms that the integrated IAT circuit has failed.
Can I keep driving?
If the engine starts and runs normally, short necessary trips are generally manageable, but cold starting or fuel economy may suffer. Avoid continued driving if rough running or stalling develops, and arrange diagnosis because faulty temperature input can affect fueling and emissions.
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.