P0557 on Buick
Brake Booster Pressure Sensor Circuit Low
P0557 on Buick vehicles indicates brake booster pressure sensor circuit low. Au7o has documented this code across 1 Buick model — most commonly on Envision. The PCM detects voltage on the brake booster pressure sensor circuit that is lower than expected (short to ground or open). The booster pressure input is invalid. Typical repair costs on Buick range from $300 to $950, depending on the specific model and root cause.
Common Causes of P0557
- •Short to ground in sensor wiring
- •Open circuit in the sensor circuit
- •Failed brake booster pressure sensor
- •Corroded/loose connector
P0557 on Buick by Model
Buick Envision(1 issue)
- Brake Vacuum Pump / Booster Pressure Sensor Failure Triggering 'Service Brake Assist' and Hard Pedal2017-2020
Owners report a 'Service Brake Assist' message appearing while driving, immediately followed by a brake pedal that is either rock-hard and requires extreme force, or that goes unresponsive and then sinks to the floor when pumped. Two NHTSA complaints on the 2019 describe this at only about 4,300-4,700 miles. The condition is tied to the electric brake vacuum pump and its booster pressure sensor circuit - GM TSB 21-NA-107 covers 'Service Brake Assist' messages with the Service Engine Soon lamp and DTC P0557 stored.
Looking for P0557 on a different make?
View P0557 across all makes →Frequently Asked Questions
What does P0557 mean on Buick?▼
P0557 stands for "Brake Booster Pressure Sensor Circuit Low." The PCM detects voltage on the brake booster pressure sensor circuit that is lower than expected (short to ground or open). The booster pressure input is invalid. On Buick specifically, this code is documented across 1 model.
What causes P0557 on Buick vehicles?▼
Common causes on Buick: Short to ground in sensor wiring, Open circuit in the sensor circuit, Failed brake booster pressure sensor, Corroded/loose connector. Specific causes vary by model and year — see the per-model sections below.
How much does it cost to fix P0557 on a Buick?▼
Repair costs on Buick range from $300 to $950, depending on the specific model and root cause.
Which Buick models have P0557 documented?▼
Au7o has documented P0557 on 1 Buick model: Envision.