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

P2109

Throttle/Pedal Position Sensor A Minimum Stop Performance

The ECU detects that the throttle position sensor A signal at the closed-throttle stop does not match the learned minimum value. The mechanical or electrical zero reference of the throttle has drifted out of the expected range, often after cleaning, replacement or wear.

SystemPowertrain
Typegeneric / SAE
GroupP2
Range / number1 / 09

Possible causes

  • Carbon deposits on throttle plate high
  • Throttle position sensor drift high
  • Idle/throttle relearn not performed medium

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: 80–400 €
  • Estimated time: 0.3–1.5 h
  • Component: throttle position sensor
  • Component: throttle body
  • Component: throttle actuator
  • MIL / check engine light
  • emissions-relevant
  • drive cycle required
  • 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