OBD-II code · Chassis
C05CB Brake Master Cylinder Piston Position Sensor A Circuit Voltage Low
Master cylinder piston position sensor A signal voltage below expected range.
Is it safe to drive with C05CB?
The car may go into limp mode (reduced power). Get it diagnosed before a long trip.
Common causes
- Most likelySignal wire shorted to ground
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
- 1–5 h
- Emissions test
- Usually unaffected
- Parts involved
- Master Cylinder Pos Sensor A
Related codes
- C05CEBrake Master Cylinder Piston Position Sensor B Circuit Voltage Low
- C05C8Brake Pressure Sensor F Circuit/Open
- C05C9Brake Pressure Sensor Supply Circuit
- C05CABrake Master Cylinder Piston Position Sensor A Circuit Voltage High
- C05CCBrake Master Cylinder Piston Position Sensor A Circuit Range/Performance
- C05CDBrake Master Cylinder Piston Position Sensor B Circuit Voltage High
Code data: OBDex open dataset (CC0). Labour times are typical ranges, not a quote.