P2431 indicates that the Powertrain Control Module (PCM) has detected a performance or range problem with the Air System Air Flow Pressure sensor circuit on Bank 1. The sensor voltage or signal is outside the expected limits, suggesting a fault in the sensor, wiring, or related components.
The sensor itself may be failing or out of calibration, causing erratic voltage or pressure readings.
Loose, cracked, or corroded wires or pins can introduce resistance or intermittent connections that push the signal out of range.
Excessive or insufficient airflow can create pressure conditions the sensor cannot measure correctly, triggering the code.
A problem within the PCM’s sensor input circuitry can misinterpret a normal sensor signal as out‑of‑range, though this is less common.
In most cases no. The PCM is rarely the cause; the sensor, wiring, or airflow issues are far more common. Replacing the PCM should only be considered after all other possibilities are ruled out.
A severely restricted air filter can affect airflow pressure, but it usually triggers other codes first. It’s worth checking, but it is not a primary cause of P2431.
Yes. The PCM monitors the sensor continuously; if the underlying issue remains, the code will reappear after the drive cycle completes.
No. P2431 refers specifically to the Air Flow Pressure sensor circuit on Bank 1, not the Mass Air Flow (MAF) sensor, which has its own set of codes.