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

P2B30

Fan 1 Stuck On

Cooling fan 1 stays in the activated state when commanded off. The relay or control driver is welded or stuck on.

SystemPowertrain
Typegeneric / SAE
GroupP2
Range / numberB / 30

Possible causes

  • Fan relay contacts welded closed high
  • Output driver stuck on medium
  • Carbon or debris buildup preventing free movement low

Inspection / repair

  • Difficulty: medium
  • DIY: shop recommended
  • Estimated cost: 100–700 €
  • Estimated time: 0.5–3 h
  • Component: cooling fan 1
  • Component: fan relay 1
  • Component: ecm
  • MIL / check engine light
  • 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