OBD-II code · Powertrain (generic, extended)
P2BA7 NOx Exceedence - Empty Reagent Tank
NOx emissions are above the legal threshold and the ECU isolates the cause to an empty reductant tank. SCR cannot dose AdBlue/DEF.
Is it safe to drive with P2BA7?
The car may go into limp mode (reduced power). Get it diagnosed before a long trip.
Common causes
- Most likelyDEF/AdBlue tank empty - refill required
- PossibleLevel sensor reads empty incorrectly
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
- Hard
- DIY friendly
- Best left to a mechanic
- Typical labour
- 1–8 h
- Emissions test
- Likely to fail
- After the fix
- A drive cycle is needed before the light stays off
- Parts involved
- Reductant Tank, Reductant Level Sensor
Code data: OBDex open dataset (CC0). Labour times are typical ranges, not a quote.