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P21B3
Closed Loop NOx Adsorber Control At Limit - Too High
Generic · engine
Data confidence
65%
The control module detected that the Closed Loop NOx Adsorber Control At Limit value was above the expected limit.
TuningBot DTC Database · v4.37.14
P21B3 Closed Loop NOx Adsorber Control At Limit - Too High
Generic (OBD-II) interpretation in the TuningBot DTC database.
What P21B3 means
Related and nearby codes
How to read P21B3
P
Powertrain: engine, transmission and driveline systems.
2
Generic SAE-standard code: same meaning on every make.
1B3
Specific fault index within the subsystem.
Frequently asked questions about P21B3
What does P21B3 mean?
Closed Loop NOx Adsorber Control At Limit - Too High. The control module detected that the Closed Loop NOx Adsorber Control At Limit value was above the expected limit.
Is P21B3 generic or manufacturer-specific?
P21B3 is a generic OBD-II code: it has the same meaning on every make and model that follows the SAE standard.
Can TuningBot remove P21B3 at file level?
If the fault logic lives in the ECU calibration, yes: our DTC Removal file service disables the specific fault entry and, where the ECU needs it, corrects the checksum too. Not sure whether your case qualifies? Request a free assessment and our engineers will check your ECU file.
Other file services
Understand the system behind this code: SCR / AdBlue System