What does code P21B6 mean?

Q: What does code P21B6 mean?

Cold Start Cylinder 1 Injection Timing. P21B6 indicates that the engine control module has detected an out-of-range condition in the cold-start fuel injection timing for cylinder 1, meaning the commanded injection timing during a cold start does not match expected values. The computer sets this code when the calculated injection timing deviates from the manufacturer's calibrated strategy during the cold-start phase, often due to mechanical or electrical faults in the fuel injection system.

DTC codes / P21xx · Fuel and air metering / P21B6

P21B6Cold Start Cylinder 1 Injection Timing

P21B6 indicates that the engine control module has detected an out-of-range condition in the cold-start fuel injection timing for cylinder 1, meaning the commanded injection timing during a cold start does not match expected values. The computer sets this code when the calculated injection timing deviates from the manufacturer's calibrated strategy during the cold-start phase, often due to mechanical or electrical faults in the fuel injection system.

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.