P0113 indicates that the engine computer is seeing a voltage signal from the intake air temperature (IAT) sensor that is higher than expected, which typically means the circuit is open or the sensor is disconnected. The computer interprets the high voltage as an extremely cold intake temperature, which can cause incorrect fuel calculations.
The wiring plug at the IAT sensor is loose, corroded, or not fully seated, creating an open circuit that causes the high-voltage reading.
A broken wire, chafed insulation, or rodent damage between the sensor and the engine computer interrupts the signal return path.
The thermistor inside the sensor has failed open internally, producing an out-of-range high voltage signal to the computer.
The pins at the engine computer side of the harness are corroded or pushed back, preventing proper circuit completion.
An internal failure in the computer's input circuit is extremely rare for this code and should only be considered after all wiring and sensor checks are exhausted.
The vehicle is usually drivable, but the engine computer may miscalculate fuel delivery, leading to poor economy and rough running. It should be diagnosed and repaired promptly.
On many vehicles the IAT sensor is integrated into the mass airflow (MAF) sensor assembly, while on others it is a separate standalone sensor in the intake duct. Check the specific vehicle's design before replacing anything.
No. PCM failure is rarely the cause of this code. The vast majority of P0113 cases are caused by a disconnected connector, damaged wiring, or a failed sensor. Replacing the computer should be a last resort only after thorough electrical testing confirms all external components are good.
No. A dirty air filter affects airflow but does not change the electrical signal from the IAT sensor. P0113 is an electrical circuit problem, not an airflow restriction issue.