P0557 Fault Code

Brake Booster Pressure Sensor Circuit Low Input

• What does that mean?
• Symptoms
• Causes
• Solutions

The P0557 error code refers to an issue with the brake booster pressure sensor. This sensor is crucial for monitoring the vacuum pressure within the brake booster, which assists in providing the necessary force for effective braking. When the sensor detects a low input, it signals the engine control unit (ECU) that there may be issues with brake efficiency, potentially compromising vehicle safety.

What are the symptoms of the P0557 code?

Drivers may notice several symptoms associated with this code:

• Warning lights illuminated on the dashboard (usually the brake or check engine light)
• A noticeable decrease in brake performance or responsiveness
• Difficulty in pressing the brake pedal or a feeling of excessive stiffness
• Unusual hissing sounds coming from the brake area
• Engine stalling or rough idling in some cases

What causes the P0557 code?

Several factors can lead to a P0557 fault code, including:

• A malfunctioning or faulty brake booster pressure sensor
• Issues with the wiring or connections to the sensor, such as shorts or breaks
• Vacuum leaks in the brake booster system
• A failing brake booster itself
• ECU programming errors or faults

How to fix P0557?

To resolve the P0557 fault code, the following steps should be taken:

1. Perform a diagnostic scan to confirm the code and check for related codes.
2. Inspect the brake booster pressure sensor and its wiring for any signs of damage, corrosion, or loose connections.
3. Check the brake booster for vacuum leaks and ensure compliance with manufacturer specifications.
4. Replace the brake booster pressure sensor if it is found to be faulty.
5. Reprogram or reset the ECU as necessary after repairs to ensure proper functioning.
6. Test drive the vehicle to ensure the repair was successful and that no further symptoms persist.