OBD-II reference

All 9.533 generic OBD-II codes, explained in detail.

Causes, inspection steps and sources — a comprehensive DIY archive. Created and maintained with love for the detail. Good luck and have fun!

Chassis generic / SAE

C0131

Master Cylinder Pressure Sensor Range/Performance

The ABS or stability control module has detected an implausible signal from the master cylinder brake pressure sensor. This sensor reports driver brake input and is used by ABS and ESP for control decisions.

SystemChassis
Typegeneric / SAE
GroupC0
Range / number1 / 31

Possible causes

  • Pressure sensor failed high
  • Wiring or connector fault medium
  • Air in brake system causing erratic pressure low

Symptoms

  • ABS warning light on
  • ESC/stability control deactivated
  • Possible reduced brake assist
  • Speedometer may behave erratically

Inspection / repair

  • Difficulty: medium
  • DIY: shop recommended
  • Estimated cost: 150–700 €
  • Estimated time: 0.5–2.5 h
  • Component: master cylinder pressure sensor
  • Component: abs control module
  • Component: esp control module

Sources

References

How to read OBD-II codes

The first letter names the vehicle system, the second digit distinguishes generic from manufacturer-specific, the remaining digits group fault area and number.

PPowertrain: engine, transmission, emissions
BBody: chassis trim, comfort, interior
CChassis: suspension, brakes, steering
UNetwork: CAN, control modules, communication