Fuel & air metering · Powertrain · generic (SAE-defined)
P0111: Intake Air Temperature Sensor 1 Circuit Range/Performance (Bank 1)
P0111 means the intake air temperature (IAT) sensor is giving readings that are electrically valid but do not make sense compared with other temperature data or expected behavior.
Standard title per SAE J2012 / ISO 15031-6 · Updated 2026-11-07 · By CarWhere Research
How P0111 sets
The powertrain control module (PCM) checks the IAT reading for plausibility, for example by comparing it with coolant temperature after a long cold soak, or by looking for readings that are stuck or jump too quickly. If the IAT value fails these checks, P0111 sets. The specific tests vary by manufacturer.
Common causes of P0111
Roughly most likely first; the actual cause depends on the vehicle and needs testing to confirm.
- IAT sensor drifting out of calibration
- Intermittent connector or wiring fault
- Sensor contaminated or mounted incorrectly
- Faulty MAF assembly where the IAT is integrated
- Coolant temperature sensor fault skewing the comparison
- Engine block heater use affecting cold-soak comparisons
P0111 symptoms
- Check engine light on
- Usually no drivability symptoms
- Possible minor cold-start roughness
- Readiness monitors may not complete
How P0111 is diagnosed
- Scan for codes and note any coolant temperature codes
- After an overnight cold soak, compare IAT, coolant and ambient temperatures
- Watch IAT in live data for stuck values or sudden jumps
- Inspect the connector and wiring
- Measure sensor resistance at known temperatures
- Replace the sensor if readings are inaccurate
Typical fixes for P0111
- Replace the IAT sensor
- Replace the MAF assembly if the sensor is integrated
- Repair intermittent wiring or connector faults
- Repair the coolant temperature sensor if it is the inaccurate one
Replace parts only after testing confirms the cause — a code names the circuit or condition that failed a check, not necessarily the faulty part. We don’t publish per-repair prices; for what households actually spend on upkeep, see car repair costs.
Related codes & warning lights
P0111 FAQ
What does code P0111 mean?
P0111 means the intake air temperature (IAT) sensor is giving readings that are electrically valid but do not make sense compared with other temperature data or expected behavior. The standard definition is "Intake Air Temperature Sensor 1 Circuit Range/Performance (Bank 1)."
Can I drive with a P0111 code?
Yes, it usually has little effect on how the vehicle runs. Repair it when convenient so the engine computer gets accurate air temperature data and emissions monitors can complete.
Can a block heater cause P0111?
On some vehicles it can, because the coolant warms while the intake air stays cold, which the PCM may see as a mismatch after a cold soak.
Is P0111 an electrical fault?
Not necessarily. It means the reading is implausible, which can come from a drifting sensor rather than an open or shorted circuit.
Keep researching
Engine guides by brand (known issues, specs)
More fuel & air metering codes
Sources
- SAE J2012 — Diagnostic Trouble Code Definitions (standard code titles)
- ISO 15031-6 — Road vehicles: communication between vehicle and external equipment for emissions-related diagnostics, Part 6: Diagnostic trouble code definitions
- U.S. EPA — Vehicle Emissions Inspection and Maintenance (I/M) programs
- U.S. EPA, 40 CFR 86.1806-17 — Federal onboard diagnostics requirements for light-duty vehicles
- California Air Resources Board — On-Board Diagnostic (OBD) Program
General information written by CarWhere Research, not a diagnosis of your vehicle. Manufacturers can add their own sub-definitions and test conditions; confirm with the factory service information for your year, make and model. Before paying for a repair, check NHTSA for open recalls and your warranty booklet: federal law requires an emissions warranty on major emission-control parts such as the catalytic converter and engine computer.