What Does P2574 Mean?
The PCM is receiving a voltage signal from the Direct Ozone Reduction catalyst deterioration sensor that is below the acceptable threshold. This indicates a low voltage condition in the sensor circuit.
Common Causes
35%
Short to ground in sensor signal wire
30%
Failed deterioration sensor with internal short
20%
Poor or corroded connector causing voltage drop
10%
Low reference voltage supply from PCM
5%
Damaged PCM sensor input circuit
Diagnostic Steps
1
Step 1: Measure sensor output voltage with engine running (should typically be 0.1-4.5V range)
2
Step 2: Check for short to ground by disconnecting sensor and measuring circuit resistance to ground
3
Step 3: Verify 5V reference voltage is present at sensor connector with key on, engine off
4
Step 4: Inspect wiring harness for damage, especially where it routes near hot or moving components
5
Step 5: Substitute known-good sensor to verify if sensor or circuit is at fault
Estimated Repair Cost
$150 - $550
Parts + labor, varies by vehicle and location
The PCM is receiving a voltage signal from the Direct Ozone Reduction catalyst deterioration sensor that is below the acceptable threshold. This indicates a low voltage condition in the sensor circuit.
The most common cause of P2574 (Direct Ozone Reduction Catalyst Deterioration Sensor Circuit Low) is: Short to ground in sensor signal wire
Typical repair costs for P2574 range from $150 to $550, depending on the vehicle, location, and whether you do it yourself or go to a shop.
Safe to drive but requires timely repair. Emissions system monitoring is impaired and may cause test failure.
Start by connecting an OBD2 scanner to read the code and any freeze frame data. Then follow the diagnostic steps specific to P2574 to identify the root cause.
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Quick Info
Category
Powertrain
System
Emissions Control System
Difficulty
Type
Generic (SAE)
Recommended Tools
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