P0555 signals a fault in the brake booster pressure sensor circuit, which monitors vacuum pressure to support the brake assist system. The code is triggered when the sensor or its circuit does not operate as expected.
The sensor itself can degrade or short out, providing incorrect pressure readings that trigger the code.
Corrosion, breaks, or loose pins in the sensor circuit can interrupt the signal between the sensor and the PCM.
A leak reduces booster pressure, causing the sensor to detect abnormal readings that the PCM flags as a fault.
A rare issue where the power‑train control module misinterprets sensor data or fails to process the circuit correctly.
It means the brake booster pressure sensor circuit is not operating within expected parameters, often due to a bad sensor, wiring issue, or vacuum leak.
Driving is possible but not recommended, as brake assist may be reduced and the pedal could feel harder, increasing stopping distance.
Usually not; most cases are resolved by repairing or replacing the sensor, wiring, or fixing a vacuum leak. PCM replacement is only considered after all other causes are eliminated.
If the underlying issue is fully resolved and the system completes several drive cycles without detecting the fault, the code may clear automatically.