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!

Powertrain generic / SAE

P211A

Throttle Actuator B Control System - Stuck Open

Throttle B is mechanically stuck open — typically carbon buildup or a broken return spring on the secondary throttle plate.

SystemPowertrain
Typegeneric / SAE
GroupP2
Range / number1 / 1A

Possible causes

  • Carbon buildup holds plate open high
  • Return spring broken medium
  • Carbon or debris buildup preventing free movement low

Symptoms

  • Check engine light on
  • Reduced throttle response, possible limp mode
  • Hesitation or surging
  • Idle too high or too low

Inspection / repair

  • Difficulty: medium
  • DIY: possible
  • Estimated cost: 80–700 €
  • Estimated time: 0.5–3 h
  • Component: throttle actuator b
  • MIL / check engine light
  • emissions-relevant
  • limp mode possible

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