C0277

Brake Booster Vacuum Sensor Circuit Malfunction

Moderate severity

The brake control module has detected an implausible signal from the booster vacuum sensor. Loss of vacuum signal can cause hard pedal and reduced power assist.

Common causes

Vacuum sensor failed
One of the most commonly reported causes for this code — check this first.
high
Typical part cost: $90-550
Vacuum leak in booster or hose
A plausible cause — test and verify before replacing parts.
medium
Typical part cost: $90-550
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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

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Frequently asked questions

What does C0277 mean?

C0277 means "Brake Booster Vacuum Sensor Circuit Malfunction". It is a generic OBD-II code that points to a fault in the chassis.

What are the most common causes of C0277?

vacuum sensor failed; vacuum leak in booster or hose — 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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