Reductant Quality Sensor Circuit Low
The P206C code indicates that the reductant quality sensor circuit in the diesel exhaust fluid (DEF) system is reading a voltage lower than the manufacturer's specified range. This sensor monitors the quality of the DEF to ensure proper selective catalytic reduction (SCR) operation. A low circuit condition can be caused by a faulty sensor, wiring issues, or a poor connection, potentially leading to incorrect DEF quality readings and reduced emissions control.
1. Most Common Causes
- Faulty reductant quality sensor
- Damaged or corroded wiring/connectors in the sensor circuit
- Short to ground in the sensor signal circuit
- Open circuit in the sensor reference voltage or ground
2. Symptoms You Will Notice
- Check Engine Light illuminated
- Reduced engine performance or power
- Increased diesel exhaust fluid consumption
- Possible limp mode activation
3. Step-by-Step Diagnosis
Step 1: Use a scan tool to retrieve all stored codes and freeze frame data.
Step 2: Visually inspect the reductant quality sensor and its wiring for damage, corrosion, or loose connections.
Step 3: Test the sensor's voltage reference and ground circuits with a multimeter.
Step 4: If circuits are okay, test the sensor's signal voltage output; compare to manufacturer specs.
Step 5: Replace the sensor if it fails testing; clear codes and test drive.
4. 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 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.
5. Commonly Affected Makes
This is a generic OBD2 code, potentially applicable to any manufacturer using this diagnostic standard.