P0556 – BMW DTC

BMW DTC P0556 – Brake Booster Pressure Sensor Circuit Range/Performance

DTC P0556 meaning on BMW

DTC P0556 on a BMW indicates an issue with the brake booster pressure sensor circuit. The powertrain control module (PCM) monitors the signal from the brake booster pressure sensor to ensure it falls within the expected range. If the signal is outside of this range or not performing as expected, the DTC P0556 is triggered.

BMW DTC P0556 symptoms

Symptoms of DTC P0556 on a BMW may include:

• Check Engine Light (CEL) illuminated on the dashboard
• Braking performance may be affected
• Loss of power assist in the braking system

BMW DTC P0556 causes

Common causes of DTC P0556 on a BMW include:

• Malfunctioning brake booster pressure sensor
• Wiring or connector issues in the brake booster pressure sensor circuit
• Faulty PCM

BMW DTC P0556 seriousness

DTC P0556 should not be ignored as it can affect the proper functioning of the braking system in your BMW. Loss of power assist in the brakes can compromise vehicle safety and should be addressed promptly.

How to diagnose DTC P0556 on BMW

To diagnose DTC P0556 on your BMW, you can follow these steps:

1. Use a diagnostic scanner to retrieve the fault codes stored in the PCM
2. Inspect the brake booster pressure sensor and its wiring for any visible damage
3. Test the brake booster pressure sensor using a multimeter to check for proper voltage and resistance
4. Check the connectors and wiring in the circuit for any loose connections or corrosion

How to fix DTC P0556 on BMW

To fix DTC P0556 on your BMW, you can try the following:

1. Replace the brake booster pressure sensor if it is found to be faulty
2. Repair or replace any damaged wiring or connectors in the circuit
3. If the issue persists, consider having the PCM checked and potentially replaced by a qualified mechanic

How to erase DTC P0556 on BMW

To erase DTC P0556 on your BMW, you can:

1. Use a diagnostic scanner to clear the fault codes stored in the PCM
2. After fixing the underlying issue causing the DTC, clear the codes again to ensure they do not reappear

Recommended tools & DTC Scanners for BMW

Best Diagnostic App for modern BMWs: BimmerLink

Recommended Bluetooth adapter for Bimmerlink: OBDLink CX

Cable adapter for Bimmerlink: Enet Cable USB Type C

For older BMWs we recommend: Autel AutoLink AL319 (2024 version)

Easy-to-use Multimeter for reliable diagnostics: AstroAI Auto-ranging Multimeter

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