Powertrain
generic / SAE
P0557
Brake Booster Pressure Sensor Circuit Low
Same as P0555 with the signal voltage below the plausible range. Boost control tracks commanded vs. actual manifold pressure; persistent deviation means wastegate, vanes, hose or actuator are not delivering the requested pressure.
SystemPowertrain
Typegeneric / SAE
GroupP0
Range / number5 / 57
Possible causes
- Signal shorted to ground high
- Connector pins corroded - high contact resistance low
- Harness chafing through insulation low
Symptoms
- Check engine light on
- Significant power loss / limp mode
- Possible blue or black smoke from exhaust
- Whistling or hissing sound from intake
Inspection / repair
- Difficulty: easy
- DIY: possible
- Estimated cost: 80–320 €
- Estimated time: 0.4–1.4 h
- Component: brake booster pressure sensor
- MIL / check engine light
Sources
References
sae:J2012