P2571 indicates the powertrain control module has detected an intermittent or erratic signal from the temperature sensor monitoring the direct ozone reduction catalyst. This catalyst, mounted in the radiator or HVAC intake, converts ambient ozone to oxygen. The code sets when the sensor voltage fluctuates outside expected limits or drops out repeatedly during operation.
The sensor element or its internal wiring fails intermittently, producing erratic resistance or voltage readings.
Chafed, corroded, or loose wiring between the sensor and the control module creates intermittent contact.
Sensor harness rubs against hot surfaces or moving components, causing intermittent shorts or opens.
Moisture, corrosion, or backed-out pins in the sensor connector produce unstable signals.
Internal driver or pull-up resistor for the sensor circuit fails intermittently; rare and only after wiring and sensor are verified.
The direct ozone reduction catalyst is not part of the regulated exhaust emissions system; the code typically has no effect on drivability or tailpipe emissions.
The vehicle will run normally, but the check engine light will remain on and the catalyst monitor may not complete, which can prevent a readiness test pass in some jurisdictions.
No. The vast majority of P2571 repairs are resolved by replacing the sensor or repairing its wiring. Control module failure is rare and should only be considered after the sensor and circuit are verified.
It is typically mounted on or near the catalyst assembly in the front radiator area or HVAC intake duct, depending on vehicle design.