What does code P21BC mean?

Q: What does code P21BC mean?

Cold Start Cylinder 7 Injection Timing. P21BC indicates that the engine control module (ECM) has detected an out-of-range condition in the cold-start injection timing strategy specifically for cylinder 7. During a cold start, the ECM commands a particular injection timing advance to improve combustion stability and reduce emissions, and this code sets when the measured or calculated timing for cylinder 7 deviates from the expected value.

DTC codes / P21xx · Fuel and air metering / P21BC

P21BCCold Start Cylinder 7 Injection Timing

P21BC indicates that the engine control module (ECM) has detected an out-of-range condition in the cold-start injection timing strategy specifically for cylinder 7. During a cold start, the ECM commands a particular injection timing advance to improve combustion stability and reduce emissions, and this code sets when the measured or calculated timing for cylinder 7 deviates from the expected value.

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.