Kühlmittelstand des Wechselrichters zu niedrig

The power electronics' own cooling loop running short of coolant — a level nobody checks, in a reservoir many owners do not know exists. The loop is separate from the engine's cooling system, with its own small tank, and a full engine coolant bottle proves nothing about it: that misdirection is the whole reason this cause earns a page.

Coolant does not vanish on its own, so a low level is a leak or a never-completed fill after earlier work. The consequence arrives on warm days: the inverter derates or cuts drive as it heats, recovers after cooling, and looks intermittent. Checking the level is a thirty-second job that resolves a disproportionate share of inverter temperature and performance codes — it just has to be the right reservoir.