P0111: Intake Air Temperature Sensor 1 Circuit Range/Performance

What does P0111 mean?

The intake-air temperature input is implausible for the conditions or does not change as expected. The signal can remain electrically within range yet still be wrong, so this differs from a simple high- or low-input fault.

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

Common causes

• Drifting IAT sensor
• Poor sensor or computer connection
• Intermittent open or short in the IAT circuit

Symptoms

• Check engine light
• Often no noticeable driving change
• Possible fueling or starting irregularity

Diagnostic focus

After sitting overnight, temperature readings should be reasonably consistent with ambient conditions. Heat soak after driving is normal and should not be mistaken for a cold-start sensor error.

Can I keep driving with P0111?

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 IAT, coolant, and ambient temperature after a cold soak
• Inspect the sensor plug and intake installation
• Test sensor resistance at the specified temperatures

Sources & review

• OBD-Codes.com: P0111
• 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.