What does code P21F0 mean?

Q: What does code P21F0 mean?

Cylinder 11 Injector B Circuit Low. P21F0 indicates that the powertrain control module (PCM) has detected an abnormally low voltage or current on the control circuit for injector B on cylinder 11, which is typically the second injector in a dual-injector arrangement on that cylinder. The PCM monitors the circuit and sets this code when the signal falls below the expected threshold, often indicating a short to ground, an open circuit, or a faulty injector.

DTC codes / P21xx · Fuel and air metering / P21F0

P21F0Cylinder 11 Injector B Circuit Low

P21F0 indicates that the powertrain control module (PCM) has detected an abnormally low voltage or current on the control circuit for injector B on cylinder 11, which is typically the second injector in a dual-injector arrangement on that cylinder. The PCM monitors the circuit and sets this code when the signal falls below the expected threshold, often indicating a short to ground, an open circuit, or a faulty injector.

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.