Неисправный датчик положения привода коромысла

The sensor confirming a switching rocker arm has actually changed state, faulty. The module commands a lift change and then waits to be told it happened — and without confirmation it will not proceed, because switching the mechanism without knowing its position risks the valvetrain.

So a sensor fault disables a healthy system. Lift changes are suppressed, the engine runs permanently on one profile, and the complaint is a flat top end or poor low-speed running depending on which profile it is stuck in. The codes name actuator performance rather than the sensor, which sends the work to the wrong part.

Oil condition matters more here than almost anywhere, since these mechanisms and their sensors sit in oil galleries fed through fine screens that sludge blocks. Check the oil, its level and the screen behind the solenoid before ordering a sensor — and a sensor reporting no movement may be telling the truth, which is a mechanical finding rather than an electrical one.