The control module detected that the air-fuel mixture stayed leaner than the target despite full corrective control (Fuel Control System B).
TuningBot DTC Database · v4.37.14
P21FC Fuel Control System B Too Lean at Higher Load Bank 1
Generic (OBD-II) interpretation in the TuningBot DTC database.
What P21FC means
Related and nearby codes
How to read P21FC
Powertrain: engine, transmission and driveline systems.
Generic SAE-standard code: same meaning on every make.
Specific fault index within the subsystem.
Frequently asked questions about P21FC
What does P21FC mean?
Fuel Control System B Too Lean at Higher Load Bank 1. The control module detected that the air-fuel mixture stayed leaner than the target despite full corrective control (Fuel Control System B).
Is P21FC generic or manufacturer-specific?
P21FC is a generic OBD-II code: it has the same meaning on every make and model that follows the SAE standard.
Can TuningBot remove P21FC 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: Diagnostic Strategy and DTC Logic
