Chassis, generic

C056C Brake Pressure Sensor B Intermittent/Erratic

Check engine lightUsually off
EmissionsNot relevant
Drive cycleNot required
Limp modePossible

C056C is the intermittent fault of the second brake pressure sensor, B. Which pressure B measures depends on the system – in Ford's hybrid ABS modules the two sensors read different points of the hydraulic unit, and other makers fit sensor B in a separate circuit or in the boost chamber. No maker documents C056C publicly. By analogy with sensor A (Ford C056B: corrupted sensor data or a missing control response for 70 ms), the code points to brief signal loss rather than lasting drift, which belongs under C0541. Honda's patent shows how a pressure sensor is judged: if pedal stroke rises but pressure does not follow, the sensor is deemed faulty. Typically stability functions shut down until the next start.

Likely causes

Intermittent contact at the sensor B connector or harness
Sensor B electronics dropping out under heat or vibration
Poor ground or unstable reference voltage

Symptoms

  • Sporadic ABS or stability warning
  • Traction and stability control briefly unavailable
  • No noticeable change in normal braking

Repair estimate

DifficultyMediumWorkshop job
Parts and labour€40–1,500
Time0.5–3 h

Typical range across vehicles; the real cost depends on what the testing finds.

Parts involved

brake pressure sensor b

Related codes

C056BC0541C0542C0543C0544

References: fordservicecontent.com, patents.google.com, saabwisonline.com, bosch-mobility.com.