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

C0571

Active Brake Assist Performance

The brake assist or driver assistance module has detected that brake assist performance is degraded. The system may fail to autonomously build pressure during emergency braking and emergency brake assist functions are limited.

SystemChassis
Typegeneric / SAE
GroupC0
Range / number5 / 71

Possible causes

  • Active booster slow or weak high
  • Secondary fault on related sensor medium
  • System calibration required after repair low

Symptoms

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

Inspection / repair

  • Difficulty: hard
  • DIY: shop recommended
  • Estimated cost: 200–2500 €
  • Estimated time: 1–5 h
  • Component: active brake booster
  • Component: brake assist module
  • Component: brake pressure sensor

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