OBD-II code · Powertrain (generic, extended)
P205C Reductant Tank Temperature Sensor A Circuit Low
DEF tank temperature sensor A reads below lower plausibility — short to ground. 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 P205C?
Usually safe to drive in the short term. Get it diagnosed when convenient, sooner if the car drives differently.
Common causes
- Most likelyShort to ground
- Less likelyConnector pins corroded - high contact resistance
- Less likelyHarness chafing through insulation
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
Related codes
- P205AReductant Tank Temperature Sensor A Circuit
- P2ADBReductant Tank Temperature Sensor B Circuit Low
- P2059Reductant Injection Air Pump Control Circuit/Open
- P205BReductant Tank Temperature Sensor A Circuit Range/Performance
- P205DReductant Tank Temperature Sensor A Circuit High
- P205EReductant Tank Temperature Sensor A Circuit Intermittent/Erratic
- P205FReductant System Performance (Bank 2)
Code data: OBDex open dataset (CC0). Labour times are typical ranges, not a quote.