P2044: Reductant Temperature Sensor Circuit Low
The P2044 code indicates that the Engine Control Module (ECM) has detected a low voltage signal from the reductant temperature sensor circuit. This sensor monitors the temperature of the diesel exhaust fluid (DEF) in the selective catalytic reduction (SCR) system. A low voltage reading typically suggests a short to ground, open circuit, or a faulty sensor. This can affect the SCR system's ability to properly dose DEF, potentially leading to increased NOx emissions and triggering the check engine light.
1. Most Common Causes
- Faulty reductant temperature sensor
- Short to ground in the sensor circuit
- Open circuit in the sensor wiring or connector
- Corroded or damaged sensor connector
- ECM software or hardware issue (rare)
2. Symptoms You Will Notice
- Check Engine Light illuminated
- Reduced engine performance or power
- Increased fuel consumption
- Possible regeneration issues or DPF clogging
- Failed emissions test
3. Step-by-Step Diagnosis
Step 1: Connect a scan tool and verify the code P2044. Check for additional related codes.
Step 2: Visually inspect the reductant temperature sensor and its wiring for damage, corrosion, or loose connections.
Step 3: Using a multimeter, measure the sensor's resistance and compare to manufacturer specifications. Also check for continuity and shorts in the circuit.
Step 4: If the sensor and wiring appear okay, test the ECM's output voltage to the sensor circuit. Replace the sensor if it fails resistance tests, or repair wiring issues as needed.
4. Frequently Asked Questions
Is it safe to drive with this code?▼
It is generally safe to drive short distances, but prolonged driving may cause increased emissions and potential damage to the SCR system. It's best to diagnose and repair promptly.
How much does it cost to fix?▼
The cost typically ranges from $50 to $150 for parts and labor, depending on the exact cause and labor rates.
5. Commonly Affected Makes
This is a generic OBD2 code, potentially applicable to any manufacturer using this diagnostic standard.