C0131Master Cylinder Pressure Sensor Range/Performance
- Generic OBD-II code · Chassis
- Can trigger limp mode
- How the car detects it
- C0131 is not in the accessible J2012 lists; GM and Saab use it for the brake pressure sensor that measures master cylinder pressure inside the modulator. In the Saab 9-5 up to 2010 a signal above 4.75 V or under 0.25 V lasting 0.1 s, or a supply outside 4.4–5.6 V, sets it and ABS, TCS and ESP go out of service. The later 9-5 and the 9-4X call it Traction Control System Pressure Circuit, check the sensor against the pedal message from the body module and against vehicle deceleration, and switch off traction and stability control. GM bulletins PIC5704C to H (Sonic, Spark, Trax, Encore 2012–2022) report C0131 after a modulator swap when shipping material was left on the sensor, which then reads 5 V all the time.
- What you may notice
- Traction/stability control warning on, systems switched off
- On some models ABS lamp on as well
- Likely causes
- LikelyBrake pressure sensor in the modulator faulty or out of calibration
- PossibleShipping material left on the sensor after modulator replacement (GM)
- PossibleFault on the 5 V reference or signal circuit of the sensor
- RareIncorrect brake pedal signal used for the plausibility check
- Repair
- Medium · Usually a job for a workshop.Typical cost: €0 – €900
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.