P205B Ford Code - Reductant Tank Temperature Sensor Circuit Range/Performance

Code P205B indicates an issue with the reductant tank temperature sensor circuit, specifically a range or performance problem. This sensor monitors the temperature of the diesel exhaust fluid (DEF) in the reductant tank.

Symptoms may include an illuminated check engine light, DEF system warning messages, reduced engine power, or the vehicle entering a limp mode in severe cases.

Common causes include a faulty reductant tank temperature sensor, damaged or corroded wiring or connectors in the sensor circuit, or issues with the powertrain control module (PCM).

While it may not directly cause mechanical damage, ignoring this issue can lead to poor DEF system performance, increased emissions, and potential restrictions in engine performance.

Start by checking the wiring and connections to the reductant tank temperature sensor for damage or corrosion. Use a scan tool to monitor the sensor readings and verify if they are within the expected range.

You’ll typically need an OBDII scan tool, a multimeter to check for wiring issues, and access to the vehicle’s service manual for specific sensor specifications.

The most common repairs include replacing the reductant tank temperature sensor, repairing damaged wiring or connectors, or in rare cases, reprogramming or replacing the PCM.

You may be able to drive the vehicle for a short period, but it’s not recommended. Continued driving could lead to reduced engine performance or emissions system malfunctions.

Repair costs can vary, but replacing the reductant tank temperature sensor typically costs between $150 and $400, depending on labor and parts pricing.

In some cases, a PCM software update may resolve the issue if the problem is related to a programming glitch, but this is less common than physical component repairs.