Reductant Temperature Sensor Circuit Intermittent
The P2046 code indicates that the powertrain control module (PCM) has detected an intermittent signal from the reductant temperature sensor, which monitors the temperature of diesel exhaust fluid (DEF) in the selective catalytic reduction (SCR) system. This sensor is critical for proper DEF injection and emissions control. An intermittent circuit fault can be caused by wiring issues, connector corrosion, or a failing sensor, leading to reduced NOx conversion efficiency and potential illumination of the check engine light.
01. Most Common Causes
- Faulty reductant temperature sensor
- Damaged or corroded wiring/connectors in the sensor circuit
- Intermittent short or open circuit due to vibration or moisture
- PCM software or hardware issue (rare)
02. Symptoms You Will Notice
- Check Engine Light illuminated
- Reduced fuel economy and engine performance
- Increased diesel exhaust fluid consumption
- Possible regeneration issues or derated engine power
03. Step-by-Step Diagnosis
Step 1: Use an OBD2 scanner to confirm the code and check for related codes (e.g., P2047-P2050).
Step 2: Visually inspect the reductant temperature sensor and its wiring harness for damage, corrosion, or loose connections.
Step 3: Test the sensor resistance and compare to manufacturer specifications; replace if out of range.
Step 4: Check for intermittent faults by wiggling the wiring harness while monitoring sensor signal with a scan tool.
04. Commonly Affected Makes
05. Frequently Asked Questions
Is it safe to drive with this code?▼
It is generally safe for short trips, but prolonged driving may cause reduced engine performance, increased emissions, and potential damage to the SCR system. It is recommended 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 whether the sensor or wiring needs replacement. Sensor replacement is usually straightforward.