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

P207F

Reductant Quality Performance

The ECU has concluded that the AdBlue/DEF in the tank does not meet specification. Diagnosed by comparing expected NOx reduction against the dosed reductant volume — too much dosing for too little NOx drop indicates diluted or wrong fluid.

SystemPowertrain
Typegeneric / SAE
GroupP2
Range / number– / 7F

Possible causes

  • AdBlue diluted with water or wrong fluid filled high
  • NOx sensor drift gives false reductant-quality verdict low

Symptoms

  • Check engine light or NOx warning on
  • AdBlue/DEF level or quality warning
  • Possible no-start countdown after ignore period
  • Failed emissions inspection (NOx)

Inspection / repair

  • Difficulty: medium
  • DIY: possible
  • Estimated cost: 50–800 €
  • Estimated time: 0.5–3 h
  • Component: adblue tank
  • Component: nox sensor
  • Component: scr catalyst
  • 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