C1246Master cylinder pressure sensor fault
- Toyota/Lexus code · ABS / stability control
- Lights a warning lamp
- How the car detects it
- The sensor that measures brake-fluid pressure from the pedal gives a wrong or missing signal. The stop light switch signal is checked against it, so a faulty switch can also set this code. While this fault is stored, the skid control unit may switch off VSC (stability control) and traction control, and sometimes ABS; normal braking still works. Drive gently and have it checked.
- What you may notice
- VSC / slip indicator or ABS warning light
- Likely causes
- PossiblePressure sensor (in the brake actuator or booster)
- PossibleStop light switch or its circuit
- Sources
Backed by at least two independent sources.
From Obdaryn's Toyota/Lexus pack, exactly as the app shows it, with the public sources above. Guidance only; confirm with a workshop.