P0111 Fault Code

Intake Air Temperature Circuit Range/Performance Problem

• What does that mean?
• Symptoms
• Causes
• Solutions

The P0111 fault code indicates that there is an issue with the Intake Air Temperature (IAT) circuit, specifically related to its range or performance. The IAT sensor measures the temperature of the air entering the engine's intake system. A malfunction in this circuit can lead to poor engine performance, increased emissions, and decreased fuel efficiency.

What are the symptoms of the P0111 code?

Symptoms of a P0111 fault may include:

• Check Engine Light (CEL) illumination on the dashboard.
• Poor engine performance including stalling or hesitation during acceleration.
• Decreased fuel efficiency, leading to more frequent visits to the gas station.
• Increased emissions, which may cause it to fail an emissions test.

What causes the P0111 code?

Common causes for a P0111 fault code include:

• A faulty IAT sensor that is providing incorrect temperature readings.
• Poor electrical connections or damaged wiring in the IAT circuit.
• Issues with the Engine Control Module (ECM) that affect sensor readings.
• Contaminated or faulty air filter which impacts the airflow around the sensor.

How to fix P0111?

To resolve a P0111 fault code:

• Begin by checking the IAT sensor for proper operation and replace it if faulty.
• Inspect the wiring and connectors related to the IAT circuit for any signs of damage or corrosion, and repair as necessary.
• Test the ECU to ensure that it is functioning properly and can accurately interpret the IAT sensor's data.
• Clear the fault code and conduct a test drive to see if the issue reoccurs.