OBD-II code · Powertrain (generic)
P0555 Brake Booster Pressure Sensor Circuit
A general circuit fault is detected on the brake booster pressure sensor - the ECU cannot determine vacuum reserve in the booster, which limits the safe operation of stop-start, regenerative-braking blending, and electric vacuum pump control.
Is it safe to drive with P0555?
Usually safe to drive in the short term. Get it diagnosed when convenient, sooner if the car drives differently.
Common causes
- Most likelyOpen in sensor or wiring
Symptoms
- Check engine light on
- Significant power loss / limp mode
- Possible blue or black smoke from exhaust
- Whistling or hissing sound from intake
Repair at a glance
- Difficulty
- Easy
- DIY friendly
- Often, with basic tools
- Typical labour
- 0.4–1.4 h
- Emissions test
- Usually unaffected
- Parts involved
- Brake Booster Pressure Sensor
Related codes
- P0552Power Steering Pressure Sensor Circuit Low Input
- P0553Power Steering Pressure Sensor Circuit High Input
- P0554Power Steering Pressure Sensor Intermittent
- P0556Brake Booster Pressure Sensor Circuit Range or Performance
- P0557Brake Booster Pressure Sensor Circuit Low
- P0558Brake Booster Pressure Sensor Circuit High
Code data: OBDex open dataset (CC0). Labour times are typical ranges, not a quote.