Brake Master Cylinder Cut Off Valve
Fault on master cylinder cut-off valve — used in brake-by-wire systems to isolate the master cylinder during normal electric boost.
Affected components
- Master cylinder cutoff valve
Common causes
- High likelihood: Valve stuck or coil failed
Possible symptoms
- ABS warning light on
- ESC/stability control deactivated
- Possible reduced brake assist
- Speedometer may behave erratically
Diagnostic notes
- The malfunction indicator lamp may illuminate
- A drive cycle may be required after repair
- Reduced-power or limp mode may occur
Sources
Diagnostic information is provided for reference only. Confirm the code with a compatible scan tool and follow the vehicle manufacturer's service procedures before replacing components.