P2228 indicates that the Powertrain Control Module (PCM) has detected a low voltage condition in the barometric pressure sensor circuit, meaning the sensor is reporting a pressure reading that is lower than expected.
The sensor itself has failed or is providing an out‑of‑range signal, which is the most common cause of a low‑circuit reading.
Frayed wires, broken connectors, or corrosion can create high resistance or an open circuit, pulling the sensor voltage low.
Loose pins, bent terminals, or a dirty connector can intermittently drop the signal voltage.
A short to chassis ground anywhere between the sensor and PCM will force the circuit voltage low.
A malfunctioning PCM input driver can misinterpret a good sensor signal as low; this is rare and should be considered only after all sensor and wiring checks are cleared.
No. Replacing the PCM is rarely the correct solution for P2228. The code almost always stems from a sensor, wiring, or connector issue. PCM replacement should be a last resort after confirming the sensor and circuit are functional.
Yes. Incorrect pressure data can cause the PCM to miscalculate fuel delivery, leading to higher emissions and potentially a failed emissions test.
No. The barometric pressure sensor measures ambient atmospheric pressure, while the MAP (Manifold Absolute Pressure) sensor measures pressure inside the intake manifold. Both provide pressure data, but they are separate components.
Extreme cold or heat can temporarily affect sensor output or wiring resistance, potentially triggering a low‑circuit reading. If the code appears only under severe temperature conditions, check the sensor and wiring for temperature‑related damage.