Powertrain, generic (extended)

P2BAE NOx Exceedence - NOx Control Monitoring System

Check engine lightOn
EmissionsRelevant
Drive cycleRequired
Limp modePossible

P2BAE is tied to the system that watches NOx control itself, typically the NOx sensors and the logic that compares measured emissions with the permitted level. Regulation (EU) 2017/1151 Annex XVI allows exhaust NOx sensors to replace separate quality and consumption checks, with warning and inducement once the NOx OBD limit is passed; the heavy-duty rules keep counters for monitoring system faults. Deutz stores P2BAE-00 on its EMR L1 controllers under SPN 4090, FMI 15, as a high NOx warning from the SCR efficiency monitor. Jaguar Land Rover bulletins list P2BAE among the DEF inducement codes, mostly next to P2BAF and a root code such as P2BA9 or P249C; it clears once that cause is fixed. The driver sees the MIL and a DEF message.

Likely causes

Underlying SCR fault such as poor DEF quality or dosing pressure deviation
NOx sensor damaged, badly mounted or contaminated
Air trapped in the DEF system
Outdated engine software

Symptoms

  • MIL with DEF dosing malfunction message
  • No-restart countdown in the cluster
  • Stored together with P2BAF and a root cause code

Repair estimate

DifficultyHardWorkshop job
Parts and labour€0–2,500
Time1–5 h

Typical range across vehicles; the real cost depends on what the testing finds.

Parts involved

scr systemnox sensor

Related codes

P2BAFP2200P2BADP249CP2BA9

References: serdia.deutz.com, static.nhtsa.gov, legislation.gov.uk, legislation.gov.uk.