1. Home
  2. /
  3. Complete List of OBD2...
  4. /
  5. P0111 Code – What...

P0111 Code – What Does It Mean & How To Fix It

This is one of the most frequent OBD2 trouble codes. Read the full article below to know what it means, how to fix it, and what other codes may show related to it.


P0111 is a generic OBD-II trouble code that indicates an issue with the Intake Air Temperature Sensor 1 Circuit Range/Performance. The critical component in measuring the temperature of incoming air into the engine control module is an Intake Air Temperature sensor (NDCIAT).


The P0111 code is triggered when the powertrain control module (PCM) detects a voltage signal from the Intake Air Temperature Sensor 1 that is out of the expected range. In order to achieve optimum performance, the PCM is based on that sensor’s data for the adjustment of the air-fuel mixture, ignition timing, and various engine parameters.


The P0111 code may be activated for a number of reasons, such as:

  • Faulty Intake Air Temperature Sensor: The code may be generated by an IAT sensor that is broken or not working properly.
  • Wire Problems: The IAT sensor’s signal may be interrupted by corroded or damaged wire and connections.
  • Sensor Position: The IAT sensor can provide erroneous readings if it is placed too close to the engine or in a region where it is exposed to high heat.
  • PCM Malfunction: A malfunctioning PCM might result in inaccurate readings from the IAT sensor and activate P0111.


The following signs may appear when the P0111 code is present:

  • The Check Engine Light Is On: The check engine light on the dashboard of the car is the first obvious sign.
  • Diminished Engine Performance: Due to incorrect air-fuel mixture changes, the engine may show diminished power and performance.
  • Poor Fuel Efficiency: Poor fuel efficiency can be caused by inaccurate sensor readings that result in inefficient fuel burning.
  • Difficult Starting: In colder weather, the engine may have trouble starting.


An OBD-II scanner or a certified mechanic must follow a step-by-step procedure to properly diagnose the P0111 error code. Typically, the diagnosis entails:

  • Code reading: Use an OBD-II scanner to get the P0111 code and any associated codes.
  • Visual Inspection: Look for any rust or obvious damage in the wiring and connections of the IAT sensor.
  • Sensor testing: Check the resistance and voltage output of the IAT sensor to see if it complies with the manufacturer’s requirements.
  • Check for PCM Issues: Examine the PCM and its connections for any potential problems.

Common mistakes

Dealing with the P0111 error code might result in errors like these:

  • Ignoring the Code: Ignoring the P0111 code and the check engine light might cause the engine to run less smoothly and perhaps endanger other engine parts.
  • Replacing the Sensor Without Proper Testing: If the fundamental cause is elsewhere, replacing the IAT sensor without first confirming its operation might result in excessive costs.
  • Ignoring Wiring Problems: Failing to search for corroded or broken wiring might lead to incorrect identification of the issue.

How serious is this?

The code P0111 may not result in a vehicle breakdown immediately, so do not ignore it. Insufficient maintenance can result in reduced engine performance and fuel efficiency, as well as potential damage to other engine components.

What repairs can fix the code?

repair manuals

Possible fixes for the P0111 error code include:

  • Replacing the Intake Air Temperature Sensor: If the present IAT sensor is broken or defective, install a new one.
  • Fixing or replacing the wiring and connectors: Take care of any wiring and connection problems with the IAT sensor.
  • Moving the IAT Sensor: If the sensor’s positioning is resulting in inaccurate results, think about moving it to a better area.
  • PCM Reprogramming or Replacement: If the PCM isn’t working properly, it may need to be reprogrammed or replaced.

Related codes

Other related codes that may accompany or be triggered by P0111 include:

  • P0110 – Intake Air Temperature Sensor 1 Circuit
  • P0112 – Intake Air Temperature Sensor, 1 Circuit, Low Input
  • P0113 – Intake Air Temperature Sensor, 1 Circuit, High Input


According to the DTC code P0111, it indicates that an issue may exist with the intake air temperature sensor 1 circuit range or performance. It will help to preserve optimal engine performance, fuel efficiency, and overall vehicle reliability by addressing the problem in a timely manner.

If you encounter the check engine light with a P0111 code, seek the assistance of a qualified technician to diagnose the root cause accurately and perform the necessary repairs.

If you can understand the meaning, causes, symptoms, and possible solutions for the P0111 code, it would be useful to take some proactive steps in order to maintain a functioning vehicle. In order to prolong the lifespan of your vehicle and prevent more serious problems in the future, it is important to regularly carry out maintenance and repair work on time.

P0111 Code – What Does It Mean & How To Fix It