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.
- Check engine light: Yes
- Emissions related: Yes
- Repair difficulty: medium
Symptoms
- Check engine light on
- Failed emissions inspection
- Possibly slightly increased fuel consumption
- Sulfur (rotten egg) smell from exhaust under load
Common causes
Ordered by how often each turns out to be the cause.
- Signal wire shorted to groundCommon
- Sensor shorted internallyPossible
- Connector pins corroded - high contact resistanceLess likely
Parts involved
- Dor Temperature Sensor
- Sensor Wiring
P2569 is a generic OBD-II code defined by SAE J2012. Exact wording and diagnostic procedure vary by manufacturer and model. Code definitions are drawn from the public-domain OBDex dataset; the workshop notes are our own.