شکستگی اهرم دریچه

The linkage between an actuator and the flap it moves, broken so the flap stays put. The actuator works, its feedback may even report movement, and the flap does nothing — which is why the module reports a performance fault rather than a circuit one.

Intake manifold flaps are where this is commonest. The linkages are often plastic and live in a hot, oily environment, so they embrittle and snap at a pivot or lose a clip. The symptom is the flap's function simply absent — a flat spot at one end of the rev range for a manifold flap — with no code naming anything mechanical. Look at the linkage before testing the actuator: a broken rod or a detached ball joint is visible in seconds and is the likeliest finding on an older engine.