The P0102 code indicates that the engine control module is receiving a lower-than‑expected voltage signal from the mass airflow sensor circuit, meaning the sensor is detecting less airflow than it should. This typically points to a problem with the sensor, its wiring, or unmetered air entering the intake system.
The sensor may be internally failed or defective, causing it to output a voltage lower than the PCM expects.
Accumulated dirt, oil, or debris on the sensor wires can reduce its output signal, triggering a low‑signal condition.
Unmetered air entering the intake after the sensor reduces the measured airflow, resulting in a low voltage reading.
Corroded, loose, or broken wires/connector pins can create high resistance, dropping the sensor voltage below the required threshold.
A fault in the PCM's power supply, ground, or input circuitry can misinterpret a normal sensor signal as low, but this is uncommon.
No, PCM failure is uncommon for this code; the issue is usually the sensor, its wiring, or an intake leak.
Cleaning may resolve the code if dirt is the cause, but if the sensor is faulty it will not.
Yes, any unmetered air downstream of the MAF sensor can cause a low‑signal condition.
A severely clogged filter can restrict airflow, but it typically triggers different codes; it is not a primary cause of P0102.