P0112 indicates that the engine control module has detected a voltage signal from the intake air temperature (IAT) sensor 1 on bank 1 that is lower than the expected range, suggesting a short to ground or an open circuit in the sensor circuit.
The sensor element itself can develop an internal short, pulling the signal voltage low.
Physical damage, corrosion, or loose pins in the sensor harness can create a low‑voltage condition.
A wire rubbing against metal or a faulty splice can ground the signal line.
An open or high‑resistance ground path for the sensor can cause the ECM to read a low voltage.
An internal driver or input circuit failure in the control module can mimic a low sensor voltage, but this is uncommon.
No, the PCM is rarely the cause; most often the sensor or its wiring is at fault.
A dirty air filter does not directly cause a low voltage signal; it affects airflow, not the sensor circuit.
Only after confirming the sensor is out of specification or the wiring is intact; otherwise you may replace a good part.
Clearing the code only resets the light; the underlying fault will cause the code to return if not repaired.