P2570

Code

Generic P — Powertrain

Direct Ozone Reduction Catalyst Temperature Sensor Circuit High

Brand: Generic

Type: P — Powertrain

Views: UK: 18 EN: 35 RU: 24

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Page language: EN

Causes

Short to battery voltage on the sensor signal or reference circuit
Open or high-resistance connection interpreted as a high-voltage condition
Faulty temperature sensor (internal short or failure)
Corroded, damaged, or loose connector or wiring harness
Poor or missing ground(s) related to the sensor circuit
Faulty engine control module (rare) or software fault

Symptoms

Malfunction Indicator Lamp (MIL) illuminated
Possible reduced emissions system performance or limp strategies
Stored DTC P2570 (Direct Ozone Reduction Catalyst Temperature Sensor Circuit High)
Potential failed emissions test
Noises or performance issues are not commonly caused directly by this code but may accompany related faults

What to check

Read and record freeze-frame and live data with a scan tool; note sensor voltage/temperature values
Perform visual inspection of sensor, connector, and wiring from sensor to ECM for damage, corrosion, or disconnection
Backprobe the sensor signal and reference circuits with key on (engine off) to measure voltage
Check for proper reference voltage (usually ~5 V) and good ground at the sensor connector
Wiggle test wiring while monitoring live data to find intermittent opens or shorts
Unplug the sensor and observe if the code changes or clears (some controllers set different codes when disconnected)

Signal parameters

Typical sensor supply/reference: ~5.0 V (verify OEM spec)
Normal sensor signal: ~0.1–4.8 V depending on temperature and sensor type (verify OEM spec)
High-circuit fault trigger: signal at or near battery voltage or above the allowed maximum (commonly >4.8–5.0 V)
Open-circuit or broken sensor wiring can sometimes register as abnormally high or out-of-range voltage
Resistance vs. temperature: varies by sensor design (thermistor/NTC: resistance decreases with increasing temperature) — check OEM table

Diagnostic algorithm

Record DTC and freeze-frame data with scan tool. Note when and under what conditions the code set.
Visually inspect sensor, harness, and connector for obvious damage, corrosion, or rodent chew. Repair as needed.
With key ON (engine OFF) backprobe the sensor connector: verify reference voltage (≈5 V) and ground presence. If reference is shorted to battery, trace harness for a short to power.
Measure sensor signal voltage. A voltage at or near battery voltage indicates a short to power or failed sensor. If signal reads open/infinite resistance, measure sensor resistance at known temperatures and compare to spec.
Perform a wiggle test on harness and connector while monitoring live sensor data to reveal intermittent faults.
If wiring and connector check good, disconnect sensor and confirm code behavior. Replace sensor and clear codes if the diagnosis points to a bad sensor.
If replacement sensor does not correct the fault, trace wiring back to the ECM for shorts to voltage or signs of damage. Repair harness or repair connector as needed.
If wiring and sensor verified good, test or substitute the control module only after other causes are eliminated (module faults are uncommon).
After repair, clear codes and perform a road or soak cycle to confirm the fault does not return.

Likely causes

Damaged or shorted wiring (pinched, rubbed through, or melted)
Corroded/loose sensor connector or terminal
Failed temperature sensor element
Faulty sensor reference (5V) or sensor ground
Intermittent connector contact due to vibration or contamination

Fault status

⚠️ Status

Direct Ozone Reduction Catalyst Temperature Sensor circuit voltage above allowable range. Possible short to battery, sensor failure, or connector/wiring fault. MIL on.

🟡 Repair difficulty: Medium

⏱️ Diagnostic time: 0.5-2.0 hours