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.
Affected components
- Brake booster
- Vacuum sensor
- Brake control module
Common causes
- High likelihood: Vacuum sensor failed
- Medium likelihood: Vacuum leak in booster or hose
Possible symptoms
- ABS warning light on
- ESC/stability control deactivated
- Possible reduced brake assist
- Speedometer may behave erratically
Sources
Diagnostic information is provided for reference only. Confirm the code with a compatible scan tool and follow the vehicle manufacturer's service procedures before replacing components.