What does code P21D5 mean?

Q: What does code P21D5 mean?

Cylinder 7 Injector B Circuit/Open. P21D5 indicates that the engine control module has detected an open circuit or excessive resistance in the electrical path for cylinder 7's injector B circuit, which typically refers to the injector driver circuit on the ground side. The computer monitors current flow through the injector and flags this code when the expected electrical load is missing, meaning the injector is not being commanded to fire or the circuit is broken.

DTC codes / P21xx · Fuel and air metering / P21D5

P21D5Cylinder 7 Injector B Circuit/Open

P21D5 indicates that the engine control module has detected an open circuit or excessive resistance in the electrical path for cylinder 7's injector B circuit, which typically refers to the injector driver circuit on the ground side. The computer monitors current flow through the injector and flags this code when the expected electrical load is missing, meaning the injector is not being commanded to fire or the circuit is broken.

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.