What does code P21D6 mean?

Q: What does code P21D6 mean?

Cylinder 8 Injector B Circuit/Open. P21D6 indicates that the engine control module (ECM) has detected an open circuit or excessive resistance in the electrical path for cylinder 8's 'B' fuel injector circuit. This means the ECM cannot properly command that injector, which may cause a misfire or rough running, though some vehicles mask the symptom until higher loads.

DTC codes / P21xx · Fuel and air metering / P21D6

P21D6Cylinder 8 Injector B Circuit/Open

P21D6 indicates that the engine control module (ECM) has detected an open circuit or excessive resistance in the electrical path for cylinder 8's 'B' fuel injector circuit. This means the ECM cannot properly command that injector, which may cause a misfire or rough running, though some vehicles mask the symptom until higher loads.

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.