Powertrain, generic (extended)

P205E Reductant Tank Temperature Sensor A Circuit Intermittent/Erratic

Check engine lightOn
EmissionsRelevant
Drive cycleRequired
Limp modeNo

P205E marks a DEF tank temperature that changes faster than any real tank could. GM describes two versions: the 2018 diesel table (1.6L Cruze, 2.8L Colorado) checks whether the signal's time evolution is plausible and fails after 8 out of 10 samples taken every 500 ms, provided no electrical fault of the sensor is present; the 2025 DEF controller flags readings that jump beyond 4 °C within ten values in three of nine checks, Type A. FCA used P205E on the 2013 Ram 2500/3500 with the 6.7L Cummins and released new PCM software (18-057-15 Rev. A) because the code set when the engine block heater was plugged in, and many later Ram updates list it too. A stored P205E without other codes therefore points to software or a loose contact. Steady faults are P205C and P205D.

Likely causes

Engine control software, fixed by reflash (FCA 6.7L)
Loose or corroded contact at the tank connector
Block heater use causing a fast temperature change

Symptoms

  • MIL, often after cold starts
  • Jumping tank temperature in live data

Repair estimate

DifficultyMediumWorkshop job
Parts and labour€0–800
Time0.3–2 h

Typical range across vehicles; the real cost depends on what the testing finds.

Parts involved

reductant tank temperature sensor

Related codes

P205AP205BP205CP205DP2046P2ADD

References: gsi.ext.gm.com, gsi.ext.gm.com, static.nhtsa.gov.