Easy one-page printout for the garage or repair shop
This summary uses the existing diagnostic information shown in full below.
This code means that the computer in your car has detected that the temperature sensor in the tank holding the special fluid for cleaning exhaust gases is reading too high. It's like when a thermometer shows a temperature that's way too high for no reason.
The P205D code is triggered when the Engine Control Module (ECM) detects a high voltage signal from the reductant tank temperature sensor, indicating a temperature reading that is higher than expected.
The reductant tank temperature sensor is part of the vehicle's emissions control system. It monitors the temperature of the Diesel Exhaust Fluid (DEF) tank. A high circuit reading suggests an issue with the sensor itself, the wiring, or the ECM. This could affect the proper dosing of DEF, which is necessary for reducing NOx emissions.
• Check Engine Light is on
• Possible reduction in engine performance
• Increased emissions
• Faulty reductant tank temperature sensor
• Wiring issues such as short circuits or open circuits
• Faulty Engine Control Module (ECM)
Reductant: A substance used to reduce emissions, often Diesel Exhaust Fluid (DEF) in diesel engines.
ECM: Engine Control Module, the computer that manages engine functions.
• Use an OBD-II scanner to confirm the code.
• Inspect the wiring and connectors for damage.
• Test the reductant tank temperature sensor for proper operation.
• Replace the reductant tank temperature sensor if faulty.
• Repair or replace any damaged wiring or connectors.
• Reprogram or replace the ECM if necessary.
• OBD-II scanner
• Multimeter
• Basic hand tools
$150 - $400
Moderate
• Ford F-Series
• Chevrolet Silverado
• Ram 1500
• Regularly inspect and maintain the DEF system.
• Ensure proper DEF fluid levels.
• Check and replace sensors as needed.
Sensor Issue
• Do not ignore the Check Engine Light.
• Have the vehicle inspected by a professional.
• Regular maintenance can prevent such issues.
Check your vehicle's warranty for coverage on emissions-related components.
This code has become more common with the increased use of DEF systems in diesel vehicles to meet stricter emissions standards.
Moderate – It should be addressed soon to ensure proper emissions control.
Operating a vehicle with a malfunctioning emissions system may violate emissions regulations and contribute to environmental pollution.
• Engine running and warmed up
• DEF system active
The reductant tank temperature sensor is located in or near the DEF tank, often at the rear of the vehicle.
Q: Can I drive with a P205D code?
A: While you can drive with this code, it's recommended to fix it soon to avoid increased emissions and potential engine performance issues.
Q: How do I reset the P205D code?
A: After repairs, use an OBD-II scanner to clear the code. If the issue is resolved, it should not return.
High-End · Full-system diagnostics
A full-system bidirectional platform aimed at advanced DIY users and professional diagnostic workflows.
Network faults often require full-system access instead of a generic code reader alone.
View on Amazon
Universal · Digital multimeter
A solid entry-level multimeter for voltage, continuity, resistance, and basic electrical troubleshooting.
Helpful for checking voltage drops, grounds, and basic circuit health when modules are not communicating.
View on Amazon
Universal · Wire connectors and repair kit
Useful when diagnosis points toward damaged wiring, corroded terminals, or connector repairs.
Useful if diagnosis points toward damaged connectors, wiring, or terminal repairs.
View on AmazonThese are optional diagnostic tools, not guaranteed fixes. As an Amazon Associate I earn from qualifying purchases.