Reductant Quality Sensor Circuit Low
The P206C code indicates that the reductant quality sensor circuit in the diesel exhaust fluid (DEF) system has detected a low voltage condition. This sensor monitors the quality of the DEF (urea solution) to ensure proper NOx reduction. A low circuit signal suggests a problem with the sensor itself, its wiring, or the DEF quality, potentially leading to increased emissions and triggering the check engine light.
01. Most Common Causes
- Faulty reductant quality sensor
- Open or shorted wiring in the sensor circuit
- Poor electrical connection at the sensor connector
- Contaminated or incorrect DEF fluid
02. Symptoms You Will Notice
- Check Engine Light illuminated
- Reduced engine performance or power
- Increased diesel exhaust fluid consumption
- Possible limp mode activation
03. Step-by-Step Diagnosis
Step 1: Scan the vehicle for all codes and note any related codes (e.g., P206A, P206B).
Step 2: Visually inspect the reductant quality sensor and its wiring for damage, corrosion, or loose connections.
Step 3: Test the sensor's voltage and ground circuits using a multimeter; compare to manufacturer specifications.
Step 4: If wiring is intact, replace the reductant quality sensor and clear the code.
04. Commonly Affected Makes
05. Frequently Asked Questions
Is it safe to drive with this code?▼
It is not recommended to drive long distances with this code, as it can lead to reduced engine performance, increased emissions, and potential damage to the SCR system. Immediate diagnosis is advised.
How much does it cost to fix?▼
The cost typically ranges from $50 to $150 for diagnosis and sensor replacement, depending on labor rates and parts pricing.