What does code P21FA mean?

Q: What does code P21FA mean?

Fuel Control System B Too Lean at Idle (Bank 2). P21FA means the powertrain control module (PCM) has detected that the fuel control system for bank 2 — the side of the engine that does not contain cylinder 1 — is running too lean at idle. The PCM monitors short-term and long-term fuel trims and sees that it is adding more fuel than expected to keep the air-fuel ratio correct when the engine is idling, indicating unmetered air or a fuel delivery shortfall on that bank.

DTC codes / P21xx · Fuel and air metering / P21FA

P21FAFuel Control System B Too Lean at Idle (Bank 2)

P21FA means the powertrain control module (PCM) has detected that the fuel control system for bank 2 — the side of the engine that does not contain cylinder 1 — is running too lean at idle. The PCM monitors short-term and long-term fuel trims and sees that it is adding more fuel than expected to keep the air-fuel ratio correct when the engine is idling, indicating unmetered air or a fuel delivery shortfall on that bank.

SystemPowertrain

Code typeGeneric (all makes)

SeverityMedium

Fix difficultyIntermediate

AreaFuel and air metering

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