What it means
The reductant tank B temperature signal does not match plausibility checks against related signals. Sensor drift.
At a glance
- Usually lights the check-engine light
- Affects emissions; the car can fail an emissions test
- The engine or gearbox may go into limp mode
How it works
Reductant tank temperature sensor B reports the temperature of the corresponding tank area to the engine control module for emissions-system monitoring and control. P2ADA sets when sensor B's reading is present but implausible compared with related readings, which can point to sensor drift or a wiring problem.
Common causes
Most likely first.
- Sensor fault
- Wiring or connector fault
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)
How to diagnose it
- Read freeze-frame data and related reductant faults, then compare live tank temperature sensor B data with other available temperature readings and ambient conditions.
- Inspect sensor B's connector and wiring at the reductant tank for corrosion, damage, loose terminals, or fluid intrusion.
- After the vehicle has been parked long enough for temperatures to settle, check whether sensor B is reasonably consistent with related temperature readings.
- Test sensor B's signal, power, and ground circuits for intermittent faults or voltage drop using the wiring diagram and manufacturer's specification.
- If the wiring is sound, test tank temperature sensor B for drift and replace it if its output fails the manufacturer's specification.
Common fixes
- Repair damaged wiring or clean and secure sensor B's connector.
- Correct a poor sensor power or ground connection affecting the reading.
- Replace reductant tank temperature sensor B if its reading is implausible or out of specification.
- Clear the fault and verify sensor B agrees plausibly with related temperature readings.
Can I keep driving?
The vehicle may remain driveable, but an incorrect tank temperature reading can disrupt reductant-system monitoring and trigger AdBlue/DEF or NOx warnings, possibly followed by a restart countdown. Arrange repair promptly and heed any countdown displayed.
A code shows where the control module detected a fault, not always which part failed. Check the causes in order and confirm with a test before replacing parts. Have several codes? Check them together
This is a generic code: it means the same on every make. The car’s maker may add more detail in its own service information.