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

P0103

Mass or Volume Air Flow Circuit High Input

The MAF sensor reports an air flow value above the plausible maximum for current engine speed and load. Often indicates a sensor that is failing in a way that produces excess output, or a short to supply voltage in the signal path.

SystemPowertrain
Typegeneric / SAE
GroupP0
Range / number1 / 03

Possible causes

  • MAF sensor failed high
  • Signal wire shorted to supply voltage medium
  • Connector pins corroded - high contact resistance low

Inspection / repair

  • Difficulty: easy
  • DIY: possible
  • Estimated cost: 80–300 €
  • Estimated time: 0.3–1.5 h
  • Component: mass air flow sensor
  • Component: mass air flow sensor wiring
  • 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