The P2574: Direct Ozone Reduction Catalyst Deterioration Sensor Circuit Low code indicates that the signal or voltage from the direct ozone reduction catalyst deterioration sensor is lower than expected. This could be due to a faulty sensor, wiring problems, or poor connections. It is important to diagnose and fix this issue to maintain effective emissions control and avoid possible damage to the vehicle’s emissions system.
P2574 – Quick Overview
Code | Information |
---|---|
Meaning | P2574: Direct Ozone Reduction Catalyst Deterioration Sensor Circuit Low |
Is it serious? | Yes, as a low voltage signal may prevent the proper monitoring of the catalyst’s efficiency, resulting in increased emissions and potential vehicle compliance issues. |
Possible causes | – Low voltage or signal in the direct ozone reduction catalyst deterioration sensor circuit – Faulty direct ozone reduction catalyst deterioration sensor – Wiring or connector issues |
How to diagnose? | – Measure the voltage in the direct ozone reduction catalyst deterioration sensor circuit – Inspect and test the direct ozone reduction catalyst deterioration sensor – Check wiring and connectors – Replace faulty components if needed |
P2574 Meaning
The P2574: Direct Ozone Reduction Catalyst Deterioration Sensor Circuit Low code indicates that the voltage from the catalyst deterioration sensor is below the acceptable range. This low voltage could be caused by an open circuit, a short to ground, or a faulty sensor, preventing accurate detection of the catalyst’s condition. Accurate monitoring of the catalyst is crucial for maintaining optimal emissions control.
Step-by-step diagnostic guide
Action | Description | Tools Needed |
---|---|---|
Check for Other Related Codes | Use an OBD-II scanner to check if there are any additional codes related to the emissions system or the catalyst deterioration sensor. This can provide more insight into the issue. | OBD-II Scanner |
Measure Voltage in the Sensor Circuit | Use a multimeter to measure the voltage at the direct ozone reduction catalyst deterioration sensor circuit. Compare the readings against the manufacturer’s specifications to see if the voltage is indeed lower than required. | Multimeter |
Inspect the Catalyst Deterioration Sensor | Visually inspect the sensor for physical signs of damage, such as cracks, dirt, or corrosion, which could impact the sensor’s ability to function properly. Make sure it is securely mounted. | Flashlight, Safety Gloves |
Test the Direct Ozone Reduction Catalyst Deterioration Sensor | Use a diagnostic tool to evaluate the sensor’s output during different engine and load conditions. The output should be consistent and within the specified range; otherwise, it indicates a faulty sensor. | Diagnostic Tool, Multimeter |
Check Wiring and Connectors | Inspect all wiring and connectors related to the sensor. Look for loose connections, frayed wires, or corrosion that may cause a drop in voltage. A short to ground or an open circuit could also be responsible for the low signal. | Flashlight, Multimeter |
Repair or Replace Faulty Wiring/Connectors | If any damaged or loose wires or connectors are found, repair or replace them. Ensure that all connections are secure and clean to maintain proper voltage in the circuit. | Basic Tools, Replacement Parts |
Replace the Faulty Catalyst Deterioration Sensor | If the sensor is found to be defective after testing, replace it with a new one. Make sure the replacement sensor is compatible and properly installed. | Replacement Catalyst Deterioration Sensor |
Clear the Code and Test Drive | After completing repairs, clear the fault code using an OBD-II scanner. Run the vehicle and observe the sensor’s readings to confirm that it is functioning correctly and that no error codes return during normal driving. | OBD-II Scanner, Vehicle Owner’s Manual |
Recheck for Codes | Re-scan the vehicle using the OBD-II scanner to verify that the P2574 code has been cleared. If the code persists, further diagnostics will be necessary to determine other potential issues. | OBD-II Scanner |

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Hi, I am Juraj “Yuri” Lukacko. I got frustrated by unhelpful and scammy mechanics, so I decided to learn everything about car diagnostics myself. I test dozens of new car diagnostic tools every month along with learning new strategies to fix and customize cars. About Juraj Lukacko (Yuri)