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

P2569

Direct Ozone Reduction Catalyst Temperature Sensor Circuit Low

Direct Ozone Reduction (DOR) catalysts are coated radiator surfaces or dedicated catalysts that decompose tropospheric ozone passing over the radiator — used for low-emissions vehicles. The temperature sensor monitoring the DOR brick reads stuck low — short to ground or sensor short.

SystemPowertrain
Typegeneric / SAE
GroupP2
Range / number5 / 69

Possible causes

  • Signal wire shorted to ground high
  • Sensor shorted internally medium
  • Connector pins corroded - high contact resistance low

Symptoms

  • Check engine light on
  • Failed emissions inspection
  • Possibly slightly increased fuel consumption
  • Sulfur (rotten egg) smell from exhaust under load

Inspection / repair

  • Difficulty: medium
  • DIY: possible
  • Estimated cost: 80–400 €
  • Estimated time: 0.4–1.5 h
  • Component: dor temperature sensor
  • Component: sensor wiring
  • MIL / check engine light
  • emissions-relevant

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