Does your Volkswagen have fault code P0555 – Brake Booster Pressure Sensor Circuit after you diagnose your Volvo with an OBD-II Scanner? Read the article below and learn what causes the fault code to appear and the possible solutions to fix the problem. This guide will discuss what causes the P0555 fault code on a Volkswagen.

P0555 fault code usually comes because of a brake booster pressure sensor circuit problem. The brake pressure sensor itself may malfunction, the connector can be faulty or corroded, wires to the sensor can get damaged, or there is a problem with the Engine Control Module (ECM /  ECU / PCM).

VW P0555 Code due to Brake Booster Pressure Sensor Circuit

In addition to P0555, you may get other related codes such as P0556, P0557, P0558, and P0559. The function of the brake booster pressure sensor is to monitor the amount of engine vacuum available for the power brake booster.

Even though we troubleshoot this problem on a VW, Diagnostic Trouble Code (DTC) P0555 is a generic code. It can come in any make, including Acura, Fiat, Alfa Romeo, Nissan, Ford, Dodge, Pontiac, Chevrolet, Acura, Subaru, Hyundai, Honda, Volvo, Mercedes-Benz, and other makes. The repair procedure will be similar, but the sensor location will vary.

The brake booster pressure sensor circuit detects the vacuum available for the power brake booster. The circuit is controlled by the Engine Control Unit (ECU), which uses the sensor to adapt braking power to various situations and adjust the available vacuum used to assist brake pedal operation.


  • Brake light stays on or flashes.
  • Check engine light stays on
  • The brake pedal is difficult to press
  • The vehicle takes longer to stop.

Possible Causes

  • Faulty brake booster sensor
  • Cracked or damaged vacuum lines
  • Corroded electrical connector
  • Damaged wire harness to the sensor
  • Faulty brake booster
  • Faulty Engine Control Module (ECM)

Possible Solutions

  • Replace faulty brake booster sensor
  • Clean any corrosion built up at the sensor.
  • Update, repair or flash ECU / ECM / PCM
  • Replace damaged wires
  • Replace damaged hoses

The power brakes use the vacuum generated by the engine to make slowing down the vehicle and applying the brakes much easier. If there is a problem with the brake system and no vacuum is being delivered to the brake booster, it may be much harder to apply enough pressure to the brakes.

Code P0555 usually is an electrical circuit fault, and brakes typically still function, but without diagnosing the problem, it may be difficult to know.

We hope you find the VW P0555 Code – Brake Booster Pressure Sensor Circuit guide helpful. Check these troubleshooting and repair guides for more help on your Volkswagen.

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