What does code P21D4 mean?

Q: What does code P21D4 mean?

Cylinder 6 Injector B Circuit/Open. P21D4 indicates that the powertrain control module (PCM) has detected an open circuit or excessive resistance in the cylinder 6 injector 'B' control circuit, which typically refers to the ground-side driver wire for that injector. The PCM monitors the injector driver and sets this code when the expected electrical load is missing or out of range, meaning the injector may not receive its command to fire.

DTC codes / P21xx · Fuel and air metering / P21D4

P21D4Cylinder 6 Injector B Circuit/Open

P21D4 indicates that the powertrain control module (PCM) has detected an open circuit or excessive resistance in the cylinder 6 injector 'B' control circuit, which typically refers to the ground-side driver wire for that injector. The PCM monitors the injector driver and sets this code when the expected electrical load is missing or out of range, meaning the injector may not receive its command to fire.

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.