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

C0291

Brake Pedal Apply Sensor Circuit Malfunction

Electrical fault in the brake pedal apply sensor circuit. The module cannot reliably detect whether the brake pedal is pressed, which affects ABS, ESP and brake assist functions.

SystemChassis
Typegeneric / SAE
GroupC0
Range / number2 / 91

Possible causes

  • Pedal apply sensor failed high
  • Wiring or connector fault medium

Symptoms

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

Inspection / repair

  • Difficulty: medium
  • DIY: possible
  • Estimated cost: 100–500 €
  • Estimated time: 0.5–2 h
  • Component: brake apply sensor
  • Component: brake control module
  • Component: sensor wiring

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