P0112: Intake Air Temperature Sensor 1 Circuit Low Input

What does P0112 mean?

The IAT signal voltage is lower than allowed. In a typical thermistor circuit low voltage is interpreted as very hot intake air, not cold air; a shorted signal can therefore create an unrealistic hot reading.

Generic OBD-II definition: Intake Air Temperature Sensor 1 Circuit Low Input. Confirm applicability in your vehicle service information.

Common causes

• IAT signal shorted to ground
• Internally shorted temperature sensor
• Damaged connector or reference circuit

Symptoms

• Check engine light
• Possibly poor running or pinging under load
• Often little visible change

Diagnostic focus

Do not confuse low input with low air temperature. If the scan tool reports extreme heat on a cold engine, test the circuit before changing the air filter or cooling system.

Can I keep driving with P0112?

Severity: Medium Drive gently and get it diagnosed soon.

If the check engine light is flashing or the car runs badly, stop driving and have it checked.

Typical fixes

• Compare reported intake temperature with actual conditions
• Inspect for a grounded signal wire
• Test the sensor and circuit using the model-specific temperature/resistance chart

Sources & review

• OBD-Codes.com: P0112
• TroubleCodes.net: generic code definitions

Definitions and diagnostic background checked 2026-11-06. Generic guidance, not a substitute for the service procedure for your exact year, engine, and transmission.