Reductant Tank Temperature Sensor Circuit Low
The P205C code indicates that the reductant tank temperature sensor circuit is reading a voltage lower than the expected range. This sensor monitors the temperature of the diesel exhaust fluid (DEF) in the tank. A low voltage reading typically points to a short to ground, a faulty sensor, or a wiring issue. This can affect the DEF system's ability to properly inject fluid for emissions control, potentially leading to increased NOx emissions and triggering the check engine light.
01. Most Common Causes
- Short to ground in the sensor circuit
- Faulty reductant tank temperature sensor
- Damaged or corroded wiring/connectors
- Open circuit in the sensor signal wire
02. Symptoms You Will Notice
- Check Engine Light illuminated
- Reduced engine performance or limp mode
- Increased diesel exhaust fluid consumption
- Failed emissions test
03. Step-by-Step Diagnosis
Step 1: Use a scan tool to retrieve the code and freeze frame data.
Step 2: Visually inspect the sensor and wiring for damage, corrosion, or loose connections.
Step 3: Measure the sensor resistance and compare to manufacturer specs; replace if out of range.
Step 4: Check for shorts to ground or opens in the circuit using a multimeter.
Step 5: Clear the code and test drive to see if it returns.
04. Commonly Affected Makes
05. Frequently Asked Questions
Is it safe to drive with this code?▼
It is generally safe to drive short distances, but the vehicle may enter limp mode to protect the emissions system. Prolonged driving could lead to increased emissions and potential damage to the DEF system.
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.