What does code P21E4 mean?

Q: What does code P21E4 mean?

Cylinder 5 Injector B Circuit Low. P21E4 indicates that the powertrain control module (PCM) has detected an abnormally low voltage on the control circuit for cylinder 5 injector B, which is the second injector assigned to that cylinder in a multi-injector or staged injection system. The PCM commands a fuel pulse but sees the circuit voltage stay below the expected threshold, so it sets this code and may disable that injector to protect the driver circuit.

DTC codes / P21xx · Fuel and air metering / P21E4

P21E4Cylinder 5 Injector B Circuit Low

P21E4 indicates that the powertrain control module (PCM) has detected an abnormally low voltage on the control circuit for cylinder 5 injector B, which is the second injector assigned to that cylinder in a multi-injector or staged injection system. The PCM commands a fuel pulse but sees the circuit voltage stay below the expected threshold, so it sets this code and may disable that injector to protect the driver circuit.

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.