What does code P21BF mean?

Q: What does code P21BF mean?

Cold Start Cylinder 10 Injection Timing. P21BF indicates that the engine control module has detected an out-of-range condition in the cold-start injection timing strategy specifically for cylinder 10. During a cold start, the module commands a particular injection timing window to reduce emissions and ensure stable combustion, and this code sets when the measured or calculated timing for cylinder 10 does not match the commanded value within an acceptable margin.

DTC codes / P21xx · Fuel and air metering / P21BF

P21BFCold Start Cylinder 10 Injection Timing

P21BF indicates that the engine control module has detected an out-of-range condition in the cold-start injection timing strategy specifically for cylinder 10. During a cold start, the module commands a particular injection timing window to reduce emissions and ensure stable combustion, and this code sets when the measured or calculated timing for cylinder 10 does not match the commanded value within an acceptable margin.

SystemPowertrain

Code typeGeneric (all makes)

SeverityMedium

Fix difficultyProfessional

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.