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2018 FORD F-150
3.5L V6 EcoBoost•RWD•AUTOMATIC•gas•turbo
19 active safety recalls on this vehicle — view recalls
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Repairs418Labor1009Torque7006Fluid18DTC3210Battery2Maintenance0Recalls19
P0557high severityPowertrain

Brake Booster Pressure Sensor Circuit Low

on 2018 Ford F-150 3.5L V6 EcoBoost · RWD

What this code means

The signal voltage from the brake booster pressure sensor is lower than the expected threshold. This often points to a short to ground or a failed sensor.

Symptoms

  • Brake warning light on
  • Reduced brake assist
  • Stiff brake pedal

Common causes

  • Short to ground in sensor wiring
  • Faulty pressure sensor
  • Corroded connector
  • PCM signal fault

Diagnostic steps

  1. Retrieve trouble codes
  2. Check sensor signal voltage
  3. Inspect wiring for shorts to ground
  4. Replace sensor if circuit checks good
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