P2572 indicates that the Powertrain Control Module (PCM) has detected an abnormal voltage, resistance, or frequency in the circuit that monitors the health of the Direct Ozone Reduction Catalyst (DORC). This sensor is used on some vehicles to assess the catalyst’s ability to reduce ozone in the exhaust stream. When the sensor circuit fails to meet factory specifications, the PCM sets this trouble code and illuminates the Check Engine light.
The sensor itself can fail due to internal corrosion, heating element degradation, or mechanical damage, leading to out‑of‑range readings.
Open circuits, short‑to‑ground or short‑to‑voltage, broken insulation, or corroded terminals in the sensor harness can disrupt the signal.
Loose or oxidized connector pins can cause intermittent or high‑resistance paths, mimicking a sensor failure.
Problems with the 5 V reference line or ground path from the PCM can affect sensor operation, though this is less common.
Issues in related emissions components (e.g., EGR, diesel oxidation catalyst) can produce abnormal sensor behavior that triggers P2572.
Rarely, a PCM programming error or internal electronic fault can misinterpret the sensor data; this should be ruled out only after all other possibilities are excluded.
It is an after‑treatment component that helps break down ozone molecules in the exhaust stream, reducing harmful emissions; a sensor monitors its deterioration.
The vehicle can usually be driven short distances without immediate risk, but the underlying issue can affect emissions and fuel economy, so it should be diagnosed and repaired promptly.
In most cases, the fault lies with the sensor or its wiring. PCM replacement is rarely required and should only be considered after all other components have been verified as good.
P2572 specifically targets the DORC sensor circuit; a bad catalytic converter typically triggers separate catalyst‑efficiency codes, although severe converter failure can affect sensor readings indirectly.