C05CB
Brake Master Cylinder Piston Position Sensor A Circuit Voltage Low
Master cylinder piston position sensor A signal voltage below expected range.
- Check engine light: Yes
- Emissions related: No
- Repair difficulty: hard
Symptoms
- ABS warning light on
- ESC/stability control deactivated
- Possible reduced brake assist
- Speedometer may behave erratically
Common causes
Ordered by how often each turns out to be the cause.
- Signal wire shorted to groundCommon
Parts involved
- Master Cylinder Pos Sensor A
C05CB is a generic OBD-II code defined by SAE J2012. Exact wording and diagnostic procedure vary by manufacturer and model. Code definitions are drawn from the public-domain OBDex dataset; the workshop notes are our own.