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

P0104

Mass or Volume Air Flow Circuit Intermittent

The ECU detects intermittent signal dropouts or noise on the mass air flow (MAF) sensor circuit. The fault is not constantly present, suggesting a loose connection, intermittent wiring break, or a failing sensor under specific conditions (vibration, temperature).

SystemPowertrain
Typegeneric / SAE
GroupP0
Range / number1 / 04

Possible causes

  • MAF connector loose or corroded high
  • Wiring chafed against engine components medium
  • MAF sensor failing intermittently medium

Inspection / repair

  • Difficulty: medium
  • DIY: possible
  • Estimated cost: 40–350 €
  • Estimated time: 0.5–2 h
  • Component: mass air flow sensor
  • Component: maf connector
  • Component: maf 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