P0112 Intake Air Temperature Sensor 1 Circuit Low

P0112 indicates a low intake-air-temperature sensor 1 circuit input. The module sees a temperature-signal voltage lower than expected.

Code details

Generic OBD-II · P0

System: Fuel / Air
Code type: Generic (SAE / ISO controlled)
Standard: SAE J2012 / ISO 15031-6

Diagnostic boundary

A diagnostic trouble code reports that a monitored test failed. It does not prove one specific part is bad, and manufacturer logic can add vehicle-specific conditions.

Do not assume the intake air is actually hot or cold from the displayed value until the circuit is checked.

Symptoms of P0112

Check-engine light on, sometimes with rough or uneven running.
Hesitation, surging, or a noticeable change in fuel economy.
Occasionally hard starting or a smell of unburnt fuel.

Common causes of P0112

A failing or contaminated sensor (MAF, MAP, oxygen or air-fuel sensor).
Intake or vacuum leaks, or an exhaust leak near an upstream sensor.
Wiring, connector, or fuel-delivery problems that skew the reading.

Useful checks before replacing parts

Compare IAT live data with ambient and coolant temperature to see whether the reading is plausible.
Check for short-to-ground, damaged wiring, connector contamination, and shared sensor-ground problems.
Inspect the sensor and harness near the intake tract where service work or heat can damage wiring.

Related OBD-II codes

These nearby fuel / air entries can help compare wording and pin down the fault area.