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

P0111

Intake Air Temperature Sensor Range/Performance

The intake air temperature (IAT) sensor reading does not change plausibly with engine warm-up or after driving begins. Many vehicles share the IAT into the MAF housing; on those, MAF replacement also replaces IAT.

SystemPowertrain
Typegeneric / SAE
GroupP0
Range / number1 / 11

Possible causes

  • Sensor drifting outside specification high
  • Sensor element coated with oil or dirt medium
  • Sensor element aged beyond calibration window low

Inspection / repair

  • Difficulty: easy
  • DIY: possible
  • Estimated cost: 30–200 €
  • Estimated time: 0.2–1 h
  • Component: intake air temperature sensor
  • Component: mass air flow sensor
  • MIL / check engine light
  • emissions-relevant
  • drive cycle required

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