P205D code meaning
Reductant Tank Temperature Sensor A Circuit High
Powertrain system Generic code P20xx codes Check engine light
What P205D means
P205D is the top-of-range fault of the tank's temperature sensor. On voltage-read NTC sensors a high signal looks like extreme cold and typically comes from an open circuit, a lost ground or a short to supply: Ford's 2023 diesels set it above 4.3 V, GM's 2025 DEF controller above 4.75 V (about −40 °C, 0.5 s, Type A), and GM's 2018 diesel table above 60,000 Ω. On the 6.6L LML and 2014 Cruze GM reads a CAN raw value instead, where High means above 1022, i.e. 160 °C or more, the hot side (6 s, Type B). Ford's bulletin 18-2190 for 2011–2015 6.7L Super Duty treats P205D like P205C: new reductant heater and sender assembly plus PCM update. Hino names P205D next to P205B and P205C as a source of wrong DEF temperature input. The low end is P205C.
P205D at a glance
- Check engine lightYes, usually on
- Emissions testCan fail
- Limp modePossible
- Repair difficultyMedium
- Typical labor0.5 to 2.5 hours
- Clears after repairWhen cleared with a scanner
Symptoms of P205D
- MIL and DEF warning
- Tank heater runs although the tank is warm
- Dosing delayed after start
Common causes of P205D
- Most likelyOpen circuit, unplugged connector or broken ground
- PossibleSensor in the heater/sender assembly open internally
- Less likelySignal wire shorted to supply voltage
Check the most likely causes first. Replacing parts by guesswork is the most expensive way to clear a code.
Parts involved
Reductant tank temperature sensor
What each part of P205D means
| P | Powertrain system: engine, fuel system, ignition, emissions and transmission. |
| 2 | Generic code (second SAE range): it means the same on every make. |
| 0 | Area: fuel and air metering and auxiliary emission controls. |
| 5D | The exact fault in that area. |
What to do next
- Note P205D and any other codes stored with it: several codes together often point to one cause.
- Check for loose connectors and damaged wiring around the parts the code names.
- Check open recalls for your car: some faults are fixed for free by the dealer. Enter your VIN.
- Clear the code only after the repair. If it comes back, the fault is still there.
Buying a used car? Scan it for stored codes before you pay. A recently cleared memory can hide a problem.
Questions about P205D
What does P205D mean?
P205D means "Reductant Tank Temperature Sensor A Circuit High". P205D is the top-of-range fault of the tank's temperature sensor. It is a generic code, so it means the same on every make.
Is it safe to drive with P205D?
Drive gently and only to a workshop. With P205D the car can go into limp mode (reduced power) to protect itself.
Will P205D fail an emissions test?
Yes, it can. P205D is emissions-related, so most inspection programs fail a car while it is stored or while the check engine light is on.
How hard is P205D to fix?
Difficulty: medium. A typical repair takes 0.5 to 2.5 hours of work. This is a job for a workshop.
Will P205D clear itself after the repair?
Clear the code with a scanner after the repair. If the fault is fixed, it does not come back.