What does code P21DE mean?

Q: What does code P21DE mean?

Cylinder 2 Injector B Circuit Low. P21DE indicates that the powertrain control module (PCM) has detected an abnormally low voltage on the control circuit for the number 2 cylinder's 'B' fuel injector, which is the second injector in that cylinder's circuit. The PCM commands a ground pulse to open the injector, and when the voltage on that circuit stays below the expected threshold, the code is stored because the injector may not be opening or the circuit has a short to ground.

DTC codes / P21xx · Fuel and air metering / P21DE

P21DECylinder 2 Injector B Circuit Low

P21DE indicates that the powertrain control module (PCM) has detected an abnormally low voltage on the control circuit for the number 2 cylinder's 'B' fuel injector, which is the second injector in that cylinder's circuit. The PCM commands a ground pulse to open the injector, and when the voltage on that circuit stays below the expected threshold, the code is stored because the injector may not be opening or the circuit has a short to ground.

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.