OBD-II code · Chassis
C055D Brake Hydraulic Circuit B Leak
Brake Hydraulic Circuit B Leak: a leak has been detected in this brake-hydraulic circuit, which reduces braking pressure. Safety-critical.
Is it safe to drive with C055D?
The car may go into limp mode (reduced power). Get it diagnosed before a long trip.
Common causes
- Most likelyBrake fluid leak in circuit B
Symptoms
- ABS warning light on
- ESC/stability control deactivated
- Possible reduced brake assist
- Speedometer may behave erratically
Repair at a glance
- Difficulty
- Hard
- DIY friendly
- Best left to a mechanic
- Typical labour
- 1–6 h
- Emissions test
- Usually unaffected
- Parts involved
- Brake Circuit B
Related codes
- C055EBrake Hydraulic Circuit A Leak
- C05B0Brake Hydraulic Circuit C Leak
- C05B1Brake Hydraulic Circuit D Leak
- C055AABS Pump Motor Supply Voltage Circuit A High
- C055BABS Pump Motor Supply Voltage Circuit A Low
- C055CABS Pump Motor Supply Voltage Circuit A Range/Performance
- C055FBSCM/EBBC Hydraulic Unit Performance
- C0560Calibration Required
Code data: OBDex open dataset (CC0). Labour times are typical ranges, not a quote.