P205CReductant Tank Temperature Sensor A Circuit Low
- Generic OBD-II code · Powertrain
- Turns on the check-engine light
- Matters for the ITP
- Can trigger limp mode
- How the car detects it
- P205C reports the DEF tank temperature signal at the bottom of its range. For voltage-read NTC sensors that means implausibly hot: Ford's 2023 diesels set it below 0.165 V, VW's Touareg below 0.30 V, GM's 2025 DEF controller below 0.3 V (about 75 °C) and GM's 2018 diesel table below 200 Ω, each as short to ground. Careful with older GM trucks: on the 6.6L LML and the 2014 Cruze the value arrives as a CAN raw value, and Low means a raw value under 1, i.e. −55 °C and over 1200 kΩ, the cold side (Type A, 3 s). Ford bulletin 18-2190 replaces the reductant heater and sender assembly on 2011–2015 6.7L Super Duty when P205C appears with P2043, and Hino has P205B to P205D checked before blaming the coolant valve. The high end is P205D.
- What you may notice
- MIL and DEF warning
- Tank temperature in live data stuck at an extreme
- Tank heater not working in frost
- Likely causes
- LikelySignal wire shorted to ground
- PossibleFaulty sensor in the heater/sender assembly
- PossibleDEF in the connector bridging the terminals
- Inspection (ITP)
- Matters for the ITP. While the check-engine light is on, the car fails the emissions check.
- Repair
- Medium · Usually a job for a workshop.Typical cost: €60 – €1,200
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.