Reference meaning
What does this code mean?
The wording below belongs to the named make and communication. Match the complete code, reporting module, model year and engine before applying it.
A code identifies a detected condition, not a part that must automatically be replaced.
Narrow by vehicle
A listed vehicle is a research lead. Confirm the engine, production range and software in the manufacturer's information.
Before replacing a part
Record codes and freeze-frame data. Check battery condition, related codes and visible wiring or hose damage. Follow the vehicle's diagnostic procedure and test results before replacing parts.
Scan worksheet →Manufacturer wording
Source wording can vary by vehicle and suffix. It is shown as written, not as a universal diagnosis.
P0556Brake Booster Pressure Sensor Circuit Performance
P0556Brake Booster Pressure Sensor Circuit Performance
P0556Brake Booster Pressure Sensor Circuit Performance
Manufacturer communications
47Original wording in English
RAM
Flash: Powertrain Control Module (PCM) Updates Customers must experience a Malfunction Indicator Lamp (MIL) illumination and the vehicle exhibit/set SYMPTOM: one or more of the following Diagnostic Trouble Codes (DTCs): ● P0420 - Catalyst System Efficiency Below Threshold Bank 1. ● P0430 - Catalyst System Efficiency Below Thresh…
AUDI
This bulletin provides information when the MIL is on; DTC P258B00 or P055600.
AUDI
This bulletin provides information for when the MIL Is illuminated; DTC P258B00 or P055600.
RAM
Flash: Powertrain Control Module (PCM) Updates This bulletin involves reprogramming the PCM with the latest available software. Customers may experience a Malfunction Indicator Lamp (MIL) illumination. Upon further investigation the technician may find that one or more of the following DTCs have been set: P0556 - Brake Booster P…
Check vehicle applicability
52A listed vehicle is a research lead. Confirm the engine, production range and software in the manufacturer's information.
Can I keep driving?
A code alone cannot establish whether driving is safe. A flashing malfunction light, severe shaking, overheating, oil-pressure warning or loss of braking or steering needs prompt attention. Stop in a safe place and seek assistance when control or engine safety is affected. Follow the vehicle handbook.