Code result
P2BAB
NOx Exceedence — Reagent System Performance
High severity
What it means
The SCR system has detected that NOx emissions exceed the legal limit and the cause is traced to a performance fault in the reagent dosing system — for example a slow dosing pump, a clogged injector, or a frozen line that is not yet caught by another DTC.
Is it safe to drive?
No — stop driving
This code can put the vehicle into limp or reduced-power mode. Avoid extended driving and have the vehicle diagnosed promptly.
Most likely causes
Reductant injector clogged with crystals
highOne of the most commonly reported causes for this code — check this first.
Dosing pump output below spec
mediumA plausible cause — test and verify before replacing parts.
Reagent supply line blocked
mediumA plausible cause — test and verify before replacing parts.
Related help
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