C0273
Brake Booster Pressure Sensor Circuit Malfunction
The brake control module has detected an out-of-range or implausible signal from the brake booster pressure sensor. Brake assist and electronic boost functions may be limited.
- 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.
- Booster pressure sensor failedCommon
- Wiring or connector fault to sensorPossible
Parts involved
- Brake Booster
- Booster Pressure Sensor
- Brake Control Module
C0273 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.