What does code P21EF mean?

Q: What does code P21EF mean?

Cylinder 10 Injector B Circuit High. P21EF indicates that the powertrain control module (PCM) has detected an abnormally high voltage on the control circuit for the number 10 cylinder's 'B' fuel injector, which usually means the circuit is open or shorted to voltage. The PCM commands the injector to fire, but the feedback or driver circuit reports a voltage above the expected threshold, so the injector may not be spraying fuel at all.

DTC codes / P21xx · Fuel and air metering / P21EF

P21EFCylinder 10 Injector B Circuit High

P21EF indicates that the powertrain control module (PCM) has detected an abnormally high voltage on the control circuit for the number 10 cylinder's 'B' fuel injector, which usually means the circuit is open or shorted to voltage. The PCM commands the injector to fire, but the feedback or driver circuit reports a voltage above the expected threshold, so the injector may not be spraying fuel at all.

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.