OBD-II code · Powertrain (generic, extended)
P2043 Reductant Temperature Sensor A Circuit Range/Performance
Reductant temperature sensor A reading is within electrical range but plausibility check fails — slow response or sticks at one value through a tank-warming cycle.
Is it safe to drive with P2043?
Usually safe to drive in the short term. Get it diagnosed when convenient, sooner if the car drives differently.
Common causes
- Most likelySensor drifts or sticks
- Less likelySensor element aged beyond calibration window
- Less likelySensor mounting loose - signal damping
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
- 0.7–2.5 h
- Emissions test
- Likely to fail
- Parts involved
- Reductant Temperature Sensor
Related codes
- P2042Reductant Temperature Sensor A Circuit
- P2040Reductant Injection Air Pressure Sensor A Circuit High
- P2041Reductant Injection Air Pressure Sensor A Circuit Intermittent
- P2044Reductant Temperature Sensor A Circuit Low
- P2045Reductant Temperature Sensor A Circuit High
- P2046Reductant Temperature Sensor A Circuit Intermittent
Code data: OBDex open dataset (CC0). Labour times are typical ranges, not a quote.