P0555 - Brake Booster Pressure Sensor Circuit

Introduction

The DTC P0555 trouble code is a common problem that can occur in modern vehicles equipped with an electric brake booster system. This code indicates a malfunction in the brake booster pressure sensor circuit, which can negatively affect the performance of the braking system. In this article, we will explore the symptoms, causes, diagnosis, and solutions for the P0555 code, providing auto mechanics with a comprehensive guide to tackling this problem.

Symptoms

When a P0555 error occurs, drivers may notice several symptoms, including:

  • Engine failure warning light illuminates :
    The malfunction light on the dashboard comes on to indicate a problem.

  • Difficulty in braking :
    There may be a feeling of stiffness in the brake pedal, making it more difficult to press.

  • Increased braking distance :
    The vehicle may require a longer distance to stop safely.

  • Abnormal noises :
    Unusual sounds coming from the brake system may be heard, indicating a possible malfunction.

Cause

The causes of a P0555 error can be many and include:

  • Faulty pressure sensor :
    The sensor itself may be faulty or malfunctioning.

  • Damaged wiring :
    Wires or connectors connecting the sensor to the engine control unit (ECU) may be damaged or oxidized.

  • Problems with the engine control unit :
    A malfunction of the ECU may prevent the sensor from functioning properly.

  • Air bubble in the system :
    An air bubble in the brake booster circuit can affect the pressure.

  • Defective seals :
    Worn seals in the brake booster system can cause pressure loss.

Diagnosis

Diagnosing DTC code P0555 requires a systematic approach:

  1. OBD-II Scanner :
    Start by connecting an OBD-II scanner to confirm the presence of the P0555 code and check for any related DTC codes such as P0556 (Brake Booster Pressure Sensor Circuit High) or P0557 (Brake Booster Pressure Sensor Circuit Low).

  2. Visual inspection :
    Check the sensor wiring and connectors for signs of wear, damage or oxidation.

  3. Sensor Test :
    Use a multimeter to measure the resistance and signal of the pressure sensor. Compare the values with the manufacturer's specifications.

  4. Checking the control unit :
    Make sure the ECU is working properly and that there are no internal faults.

  5. Checking the brake booster system :
    Check for any air leaks or mechanical problems within the brake booster system.

Resolution and repair

Once the cause of the P0555 code has been identified, you can proceed with the repair:

  • Sensor Replacement :
    If the brake booster pressure sensor is faulty, replace it with an original or equivalent quality part.

  • Wiring Repair :
    If any cables are damaged, repair or replace the connections and make sure they are well insulated.

  • Replacing the engine control unit :
    If the control unit shows signs of failure, it may need to be replaced or reprogrammed.

  • Brake booster system bleed :
    If there are air bubbles in the system, perform a bleeding procedure to remove them and restore proper pressure.

  • Replacing the gaskets :
    If the seals are worn, replace them to avoid pressure loss.

Insight: Components involved in the failure

Brake Booster Pressure Sensor

The brake booster pressure sensor is a critical component that measures the pressure inside the brake booster and provides this data to the engine control unit (ECU).

  • Function :
    It allows you to optimize the operation of the brake booster, ensuring that the braking system operates efficiently.

  • Type :
    It can be analog or digital, depending on the vehicle design.

Brake Booster System

The brake booster system uses vacuum pressure or an electrical system to amplify the force applied to the brake pedal.

  • Components :
    Includes brake booster, connecting pipes, gaskets and vacuum circuit.

  • Importance :
    Proper operation is crucial to ensure vehicle safety and braking system responsiveness.

Conclusions

DTC P0555 is an indicator of problems in the brake booster pressure sensor circuit, which can compromise the safety of the vehicle. It is essential to address the symptoms and causes of this fault promptly. Through accurate diagnosis and proper repair, the performance of the brake system can be restored and a safe driving experience can be ensured. Auto mechanics must be well-informed about the components involved and the troubleshooting procedures to effectively address this problem and provide high-quality service to their customers.

Important
Not all OBD2 codes used by one manufacturer are used by other brands, and may not have the same meaning.
The information presented here is for informational purposes only. We are not responsible for any actions you take on your vehicle. If you have any concerns about repairing your vehicle, please contact your repair shop.