P0110: Intake Air Temperature Sensor 1 Circuit
P0110 means Intake Air Temperature Sensor 1 Circuit. The intake air temperature (IAT) sensor is a thermistor that tells the engine computer how warm the incoming air is. The control module has detected a fault in the circuit itself, such as an open circuit, a short, or a signal outside the electrical limits it expects. A low voltage reads as very hot air; a high voltage reads as very cold air.
Can I keep driving? Safe to drive short-term, but have it checked to avoid failed emissions or worse fuel economy.
Common symptoms
- Check engine light on
- Usually small effect on drivability
- Possible hard starting in cold weather or slightly worse fuel economy
Possible causes
- Unplugged or damaged connector
- Failed sensor (often built into the MAF sensor)
- Shorted or open wiring
How to diagnose P0110
- Check the live IAT reading: after the car has stood overnight it should be close to the outside air and coolant temperature.
- Inspect the connector, then test the signal and ground circuits.
- Unplugging the sensor should make the reading jump to its extreme value, which confirms the wiring and computer are responding.
What the code means, digit by digit
Generic codes have the same definition on every OBD-II vehicle (petrol cars from model year 1996 in the US, 2001 in the EU; diesels later). Manufacturers can add their own enhanced codes; those are not listed here.
Related codes
General guidance only. Fault codes describe what the engine computer saw, not which part failed: confirm with testing before replacing parts, and follow the vehicle's service information.