Skip to contentGarageFix
Plans and pricingFor mechanics
Sign in
← All fault codes

OBD-II · Engine and powertrain (P)

P2BA8

NOx exceedance - AdBlue dosing interrupted

What it means

NOx emissions may exceed limits because AdBlue dosing has stopped due to another fault in the system. On vehicles with SCR, a confirmed unresolved fault may trigger reduced performance or a no-restart countdown; follow the displayed warning and the vehicle handbook.

Symptoms

  • emissions warning; an AdBlue no-start countdown may appear on SCR-equipped vehicles
  • engine warning light
  • if a no-start countdown is displayed, restarting is inhibited when it reaches zero

Likely causes, most likely first

Likely causes, most likely first
No.Cause
01AdBlue pump or pressure fault
02dosing injector blocked or electrically faulty
03heater or line fault (often in winter)
04NOx sensor fault

What to check, step by step

  1. 01Read all other AdBlue/SCR codes - they show why dosing stopped.
  2. 02Fix the underlying fault (pump, injector, heater, lines).
  3. 03Clear codes and confirm dosing resumes in live data.