Fuel & air metering · Powertrain · generic (SAE-defined)
P0110: Intake Air Temperature Sensor 1 Circuit (Bank 1)
P0110 means the engine computer detected a general electrical problem in the intake air temperature (IAT) sensor circuit.
Standard title per SAE J2012 / ISO 15031-6 · Updated 2026-11-07 · By CarWhere Research
How P0110 sets
The intake air temperature (IAT) sensor is a thermistor whose resistance changes with temperature. The powertrain control module (PCM) supplies a reference voltage and reads the resulting signal. If the signal is missing, erratic or outside the normal range in a way that does not match a more specific high or low code, P0110 sets. On many vehicles the IAT sensor is built into the mass air flow (MAF) sensor.
Common causes of P0110
Roughly most likely first; the actual cause depends on the vehicle and needs testing to confirm.
- Unplugged or corroded IAT or MAF connector
- Broken or shorted IAT wiring
- Failed IAT sensor
- Faulty MAF assembly where the IAT is integrated
- PCM fault (rare)
P0110 symptoms
- Check engine light on
- Often no drivability symptoms
- Slightly rough cold idle
- Small drop in fuel economy
How P0110 is diagnosed
- Scan for codes and look at the IAT reading in live data
- Compare IAT to ambient and coolant temperature on a cold engine
- Inspect the connector and harness
- Check reference voltage and ground at the sensor
- Measure sensor resistance at a known temperature
- Repair wiring or replace the sensor or MAF assembly
Typical fixes for P0110
- Reconnect or repair the connector
- Repair wiring faults
- Replace the IAT sensor
- Replace the MAF sensor if the IAT is integrated
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.
Manufacturer notes
Older definitions call this simply "Intake Air Temperature Circuit"; newer definitions add "Sensor 1" because some engines use more than one IAT sensor. Check factory service information for which sensor applies.
Related codes & warning lights
P0110 FAQ
What does code P0110 mean?
P0110 means the engine computer detected a general electrical problem in the intake air temperature (IAT) sensor circuit. The standard definition is "Intake Air Temperature Sensor 1 Circuit (Bank 1)."
Can I drive with a P0110 code?
Yes, the vehicle is usually fine to drive because the engine computer substitutes a default air temperature. Fuel economy and cold-start behavior may be slightly affected, so plan a repair.
Where is the intake air temperature sensor?
It is in the air intake path, either as a separate sensor in the duct or air box, or built into the mass air flow sensor.
Does P0110 affect emissions?
Slightly, because air temperature helps the PCM calculate fuel and timing. The default value usually keeps the engine running acceptably.
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.