What does code P21D1 mean?

Q: What does code P21D1 mean?

Cylinder 3 Injector B Circuit/Open. P21D1 indicates that the powertrain control module (PCM) has detected an open circuit or excessive resistance in the control circuit for cylinder 3 injector B, which is the second injector assigned to that cylinder on engines equipped with dual injection. The PCM monitors the injector driver circuit and sets this code when the expected current flow is absent or out of range during commanded injection events.

DTC codes / P21xx · Fuel and air metering / P21D1

P21D1Cylinder 3 Injector B Circuit/Open

P21D1 indicates that the powertrain control module (PCM) has detected an open circuit or excessive resistance in the control circuit for cylinder 3 injector B, which is the second injector assigned to that cylinder on engines equipped with dual injection. The PCM monitors the injector driver circuit and sets this code when the expected current flow is absent or out of range during commanded injection events.

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.