OBD-II code · Chassis
C05D1 Brake Master Cylinder Piston Position Sensor Supply Circuit
Generic fault on master cylinder piston position sensor supply circuit.
Is it safe to drive with C05D1?
The car may go into limp mode (reduced power). Get it diagnosed before a long trip.
Common causes
- Most likelySupply wiring fault
Symptoms
- ABS warning light on
- ESC/stability control deactivated
- Possible reduced brake assist
- Speedometer may behave erratically
Repair at a glance
- Difficulty
- Medium
- DIY friendly
- Best left to a mechanic
- Typical labour
- 0.5–3 h
- Emissions test
- Usually unaffected
- Parts involved
- Master Cylinder Pos Sensor Supply
Related codes
- C05CEBrake Master Cylinder Piston Position Sensor B Circuit Voltage Low
- C05CFBrake Master Cylinder Piston Position Sensor B Circuit Range/Performance
- C05D0Brake Master Cylinder Piston Position Sensor A/B Correlation
- C05D2Master Cylinder Piston Position Higher Than Expected
- C05D3Driver Applied Pressure Higher Than Expected
- C05D4Brake Master Cylinder Piston Position Sensor Calibration Not Learned
Code data: OBDex open dataset (CC0). Labour times are typical ranges, not a quote.