P0556
Brake Booster Pressure Sensor Circuit Range or Performance
Same as P0555 with the signal in plausible range yet not matching the engine model - drift, partial blockage of the reference port.
Same as P0555 with the signal in plausible range yet not matching the engine model - drift, partial blockage of the reference port.
Common causes
- high
Sensor element drifted
One of the most commonly reported causes for this code — check this first.
Typical part cost: $90-350
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First things to check
- 1Confirm the code with a scan tool and check for additional related codes.
- 2Inspect the relevant sensors, wiring, and connectors for damage or corrosion.
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Related codes
See related trouble codes
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Frequently asked questions
What does P0556 mean?
P0556 means "Brake Booster Pressure Sensor Circuit Range or Performance". It is a generic OBD-II code that points to a fault in the vehicle speed, idle control, auxiliary inputs.
What are the most common causes of P0556?
sensor element drifted — these are the most commonly reported causes. Verify with a proper diagnosis before replacing parts, or use the Wrenchify app for a vehicle-specific diagnosis.
Can I keep driving with this code?
The vehicle is usually drivable for short distances, but the problem can worsen or affect emissions. Diagnose and repair as soon as practical. Use the Wrenchify app for a full diagnosis specific to your vehicle.
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