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.
Affected components
- Dor temperature sensor
- Sensor wiring
Common causes
- High likelihood: Signal wire shorted to ground
- Medium likelihood: Sensor shorted internally
- Low likelihood: Connector pins corroded - high contact resistance
Possible symptoms
- Check engine light on
- Failed emissions inspection
- Possibly slightly increased fuel consumption
- Sulfur (rotten egg) smell from exhaust under load
Diagnostic notes
- The malfunction indicator lamp may illuminate
- This code can affect emissions
Sources
Diagnostic information is provided for reference only. Confirm the code with a compatible scan tool and follow the vehicle manufacturer's service procedures before replacing components.