What does code P2BAB mean?

Q: What does code P2BAB mean?

NOx Exceedence - Reagent System Performance. P2BAB indicates that the powertrain control module has detected a nitrogen oxide (NOx) exceedance condition directly attributable to poor performance of the reagent dosing system, which is the diesel exhaust fluid (DEF) injection circuit used for selective catalytic reduction. The computer compares the NOx sensor readings downstream of the catalyst against the expected reduction efficiency and flags this code when the reagent system fails to deliver the quantity or quality of ammonia needed to keep NOx within the programmed limit.

DTC codes / P2Bxx · Hybrid propulsion / P2BAB

P2BABNOx Exceedence - Reagent System Performance

P2BAB indicates that the powertrain control module has detected a nitrogen oxide (NOx) exceedance condition directly attributable to poor performance of the reagent dosing system, which is the diesel exhaust fluid (DEF) injection circuit used for selective catalytic reduction. The computer compares the NOx sensor readings downstream of the catalyst against the expected reduction efficiency and flags this code when the reagent system fails to deliver the quantity or quality of ammonia needed to keep NOx within the programmed limit.

SystemPowertrain

Code typeGeneric (all makes)

SeverityMedium

Fix difficultyProfessional

AreaHybrid propulsion

Guidance is general and written for all OBD-II vehicles. Exact tests and values vary by model, so confirm the fault before replacing parts.