P0556 Fault Code

Brake Booster Pressure Sensor Circuit Range/Performance

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

The P0556 fault code indicates an issue with the Brake Booster Pressure Sensor Circuit, specifically relating to its range or performance. This sensor plays a crucial role in measuring the vacuum pressure in the brake booster, ensuring optimal brake performance. Any discrepancies in its readings can lead to compromised braking efficiency, which can affect vehicle safety.

What are the symptoms of the P0556 code?

Symptoms associated with P0556 may include:

• Illumination of the check engine light on the dashboard.
• A noticeable increase in brake pedal effort when braking, indicating reduced brake effectiveness.
• Intermittent brake system performance issues, such as the brakes feeling spongy or unresponsive.
• An unusual hissing or air leak noise when the brake pedal is pressed.

What causes the P0556 code?

Common causes of P0556 include:

• A faulty brake booster pressure sensor that is unable to provide accurate readings.
• Damaged wiring or connectors in the sensor circuit that can lead to poor electrical connections.
• A vacuum leak in the brake booster system that affects pressure measurements.
• Software issues within the vehicle's engine control module (ECM) that may misinterpret sensor data.

How to fix P0556?

To resolve the P0556 fault code, the following steps can be taken:

• Inspect and replace the brake booster pressure sensor if it is found to be faulty.
• Check the wiring and connectors for damage, corrosion, or loose connections, and repair or replace as necessary.
• Test for vacuum leaks in the brake booster and its associated lines, sealing any leaks found.
• If all hardware checks out, consider reprogramming or updating the ECM to ensure proper sensor data interpretation.