OBD-II code · Chassis
C0277 Brake Booster Vacuum Sensor Circuit Malfunction
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.
Is it safe to drive with C0277?
Usually safe to drive in the short term. Get it diagnosed when convenient, sooner if the car drives differently.
Common causes
- Most likelyVacuum sensor failed
- PossibleVacuum leak in booster or hose
Symptoms
- ABS warning light on
- ESC/stability control deactivated
- Possible reduced brake assist
- Speedometer may behave erratically
Repair at a glance
- Difficulty
- Medium
- DIY friendly
- Often, with basic tools
- Typical labour
- 0.5–2 h
- Emissions test
- Usually unaffected
- Parts involved
- Brake Booster, Vacuum Sensor, Brake Control Module
Code data: OBDex open dataset (CC0). Labour times are typical ranges, not a quote.