Kurzgeschlossener Injektor zieht die Endstufe herunter

An injector whose winding has partially shorted, pulling more current than its driver was designed to supply — and the reason this cause is worth naming separately is that the code you get names the driver, the module or the supply, not the injector that is actually at fault.

The mechanism is a load fault presenting as a supply fault. A shorted winding is a lower resistance than the circuit expects, so it drags the shared actuator supply rail down every time that injector is commanded. Other actuators on the same rail then see an out-of-range voltage and complain, and the module protecting itself may report its own internal driver performance. A supply voltage low code arriving together with a single cylinder's misfire is this pattern, and the supply is the symptom.

It is why replacing a control module can fail twice. The module was not faulty; it was loaded by the injector, and a new one meets the same short. Measure each injector's winding resistance against the others before fitting any module — the outlier is usually obvious, and it costs minutes against the price of the part the code appears to name.