P205E: Reductant Tank Temperature Sensor Circuit Intermittent/Erratic
The P205E code indicates that the powertrain control module (PCM) has detected an intermittent or erratic signal from the reductant tank temperature sensor, which monitors the temperature of the diesel exhaust fluid (DEF) in the tank. This sensor is critical for proper DEF dosing and selective catalytic reduction (SCR) system operation. An erratic signal can cause incorrect DEF injection, leading to increased emissions, reduced fuel economy, and potential catalyst damage. Common causes include a faulty sensor, damaged wiring, or poor electrical connections.
1. Most Common Causes
- Faulty reductant tank temperature sensor
- Damaged or corroded wiring/connectors in the sensor circuit
- Intermittent short or open in the sensor circuit
- PCM software or hardware issue (rare)
2. Symptoms You Will Notice
- Check Engine Light illuminated
- Reduced fuel economy
- Increased diesel exhaust fluid consumption
- Possible limp mode or reduced engine power
3. Step-by-Step Diagnosis
Step 1: Connect a scan tool and verify the code P205E. Check for other related codes.
Step 2: Visually inspect the reductant tank temperature sensor and its wiring for damage, corrosion, or loose connections.
Step 3: Use a multimeter to test the sensor's resistance and compare with manufacturer specifications. Also check for continuity and shorts in the wiring.
Step 4: If the sensor and wiring are okay, clear the code and test drive to see if it returns. If it does, replace the sensor.
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 increased emissions and potential damage to the SCR system. It's best 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 the vehicle and shop rates. The sensor itself is usually inexpensive.
5. Commonly Affected Makes
This is a generic OBD2 code, potentially applicable to any manufacturer using this diagnostic standard.