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

C0201

Brake Fluid Level Switch Circuit

The ABS or brake control module has detected a fault in the brake fluid level switch circuit. A low fluid level indicates a potential leak in the hydraulic system and disables ABS while a separate brake warning lamp is illuminated.

SystemChassis
Typegeneric / SAE
GroupC0
Range / number2 / 01

Possible causes

  • Brake fluid level low (worn pads or hydraulic leak) high
  • Float switch in reservoir failed medium
  • Wiring or connector fault low

Symptoms

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

Inspection / repair

  • Difficulty: easy
  • DIY: possible
  • Estimated cost: 40–300 €
  • Estimated time: 0.3–2 h
  • Component: brake fluid level switch
  • Component: brake fluid reservoir
  • Component: abs 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