What does code P21B7 mean?

Q: What does code P21B7 mean?

Cold Start Cylinder 2 Injection Timing. P21B7 indicates that the engine control module has detected an injection timing error specifically for cylinder 2 during cold-start conditions, where the actual injection event does not match the commanded timing within an acceptable margin. The computer monitors crankshaft and camshaft signals along with injector actuation feedback to determine that cylinder 2's injection timing is outside the expected window when the engine is cold.

DTC codes / P21xx · Fuel and air metering / P21B7

P21B7Cold Start Cylinder 2 Injection Timing

P21B7 indicates that the engine control module has detected an injection timing error specifically for cylinder 2 during cold-start conditions, where the actual injection event does not match the commanded timing within an acceptable margin. The computer monitors crankshaft and camshaft signals along with injector actuation feedback to determine that cylinder 2's injection timing is outside the expected window when the engine is cold.

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.