P0558 Fault Code

Brake Booster Pressure Sensor Circuit High Input

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

The P0558 fault code refers to a problem with the Brake Booster Pressure Sensor Circuit, specifically indicating a high input signal. This sensor is crucial for monitoring the brake booster pressure, which helps in maintaining adequate braking performance. A high input signal may suggest that there is an issue with the sensor itself or the circuit that connects it to the vehicle’s computer. Common symptoms associated with this fault include a warning light on the dashboard, poor brake performance, or increased effort to press the brake pedal.

What are the symptoms of the P0558 code?

Symptoms that might be experienced when a P0558 code is present include:

• Illuminated brake warning light on the dashboard
• Noticeably increased brake pedal effort
• Reduced braking power
• Unusual noises when braking, such as hissing or whistling
• A feeling of spongy brakes or inconsistent brake response.

What causes the P0558 code?

Several factors can lead to a P0558 code, including:

• Faulty brake booster pressure sensor
• Damaged wiring or connectors in the sensor circuit
• Issues with the vehicle's brake booster itself
• Corrosion or poor connections at the sensor terminals
• Malfunctioning engine control unit (ECU) receiving erroneous signals.

How to fix P0558?

To resolve a P0558 fault code, the following steps can be taken:

• Inspect the brake booster pressure sensor and its wiring for any visible damage or corrosion.
• Test the sensor to ensure it operates within the manufacturer's specifications.
• Check for continuity and proper voltage in the sensor circuit.
• If the sensor or wiring is faulty, replace with new or repaired components.
• Clear the fault code with an OBD-II scanner and test-drive the vehicle to see if the issue persists.