OBD-II code · Powertrain (generic, extended)

P205D Reductant Tank Temperature Sensor A Circuit High

DEF tank temperature sensor A reads above upper plausibility — open signal or short to B+. Wiring faults of this kind typically come from chafing, water ingress at connector seals, or pin push-back — a wiggle test on the harness while the code is active often confirms the location.

Is it safe to drive with P205D?

Usually safe to drive in the short term. Get it diagnosed when convenient, sooner if the car drives differently.

Common causes

  • Most likelyOpen signal line
  • Less likelyConnector pins corroded - high contact resistance
  • Less likelySupply wire pinched against B+ source

Symptoms

  • Check engine light or NOx warning on
  • AdBlue/DEF level or quality warning
  • Possible no-start countdown after ignore period
  • Failed emissions inspection (NOx)

Repair at a glance

Difficulty
Medium
DIY friendly
Best left to a mechanic
Typical labour
0.7–2 h
Emissions test
Likely to fail
Parts involved
Reductant Tank Temperature Sensor

Code data: OBDex open dataset (CC0). Labour times are typical ranges, not a quote.