Reductant Tank Temperature Sensor Circuit High
The P205D code indicates that the reductant tank temperature sensor circuit is reading a voltage higher than the expected range. This sensor monitors the temperature of the diesel exhaust fluid (DEF) in the tank. A high voltage signal typically points to a short to power, a faulty sensor, or a wiring issue. This can affect the DEF system's ability to properly dose reductant, potentially leading to increased emissions and triggering the check engine light.
1. Most Common Causes
- Faulty reductant tank temperature sensor (internal open circuit)
- Signal circuit shorted to battery voltage (B+)
- Open signal circuit (broken wire or disconnected connector)
- Sensor connector corroded, loose, or with damaged terminals
- Internal ECM failure (uncommon)
2. Symptoms You Will Notice
- Check Engine Light illuminated
- Reduced engine performance or limp mode
- Increased diesel exhaust fluid consumption
- Possible failed emissions test
3. Step-by-Step Diagnosis
Step 1: Scan for additional codes and freeze frame data.
Step 2: Visually inspect the sensor and wiring for damage or corrosion.
Step 3: Test the sensor resistance and compare to specifications.
Step 4: Check for shorts to power or ground in the circuit using a multimeter.
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 reduced performance or limp mode. It's best to diagnose and repair promptly to avoid further issues.
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.
5. Commonly Affected Makes
This is a generic OBD2 code, potentially applicable to any manufacturer using this diagnostic standard.