C0279
Brake Booster Boost Sensor Circuit Malfunction
The brake control module has detected an electrical fault in the booster boost (assist pressure) sensor circuit. Power-assist regulation may default to a backup strategy.
- Check engine light: Not always
- Emissions related: No
- Repair difficulty: medium
Symptoms
- ABS warning light on
- ESC/stability control deactivated
- Possible reduced brake assist
- Speedometer may behave erratically
Common causes
Ordered by how often each turns out to be the cause.
- Boost sensor failedCommon
- Sensor wiring or connector faultPossible
Parts involved
- Brake Booster
- Boost Sensor
- Brake Control Module
C0279 is a generic OBD-II code defined by SAE J2012. Exact wording and diagnostic procedure vary by manufacturer and model. Code definitions are drawn from the public-domain OBDex dataset; the workshop notes are our own.