OBD-II code · Powertrain (generic, extended)
P2BA8 NOx Exceedence - Interruption of Reagent Dosing Activity
NOx emissions are above the legal threshold and the ECU isolates the cause to interruption of reductant dosing. The injection valve, pump, or supply line is impaired.
Is it safe to drive with P2BA8?
The car may go into limp mode (reduced power). Get it diagnosed before a long trip.
Common causes
- Most likelyReductant injection valve clogged
- PossibleReductant pump output insufficient
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 Injection Valve, Reductant Pump, Scr Module
Code data: OBDex open dataset (CC0). Labour times are typical ranges, not a quote.