Reductant Tank Temperature Sensor Circuit Issue
The P205A code indicates a problem in the reductant tank temperature sensor circuit, which monitors the temperature of the diesel exhaust fluid (DEF) in the tank. This sensor is crucial for proper DEF dosing and emissions control. A fault can cause the engine control module (ECM) to detect an out-of-range signal, leading to reduced engine performance or illumination of the check engine light.
01. Most Common Causes
- Faulty reductant tank temperature sensor
- Open or shorted wiring in the sensor circuit
- Corroded or loose electrical connector
- Damaged sensor due to contamination or physical impact
02. Symptoms You Will Notice
- Check Engine Light on
- Reduced engine power or limp mode
- Increased DEF consumption or dosing errors
- Possible failure of emissions tests
03. Step-by-Step Diagnosis
Step 1: Use an OBD2 scanner to confirm the code and check for related codes.
Step 2: Visually inspect the sensor and wiring for damage, corrosion, or loose connections.
Step 3: Test the sensor resistance with a multimeter and compare to manufacturer specifications.
Step 4: Check the circuit for shorts or opens using a wiring diagram and multimeter.
04. Commonly Affected Makes
05. Frequently Asked Questions
Is it safe to drive with this code?▼
It is generally safe for short distances, but prolonged driving may cause reduced engine power or increased emissions. 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 sensor price and accessibility.