What does code P2391 mean?

Q: What does code P2391 mean?

Diesel Intake Air Flow B Control Performance. P2391 indicates that the engine control module has detected a performance problem with the diesel intake air flow control system, specifically circuit B. The computer monitors the expected versus actual intake air flow and sets this code when the measured flow deviates from the commanded value beyond a calibrated threshold.

DTC codes / P23xx · Ignition system and misfire / P2391

P2391Diesel Intake Air Flow B Control Performance

P2391 indicates that the engine control module has detected a performance problem with the diesel intake air flow control system, specifically circuit B. The computer monitors the expected versus actual intake air flow and sets this code when the measured flow deviates from the commanded value beyond a calibrated threshold.

SystemPowertrain

Code typeGeneric (all makes)

SeverityMedium

Fix difficultyIntermediate

AreaIgnition system and misfire

Guidance is general and written for all OBD-II vehicles. Exact tests and values vary by model, so confirm the fault before replacing parts.