Luft im Kühlkreislauf des Wechselrichters

An airlock in the power electronics' cooling loop — the failure that follows work rather than wear. The loop's electric pump cannot push air the way it pushes liquid, so a pocket left behind after a coolant change, a pump replacement or any repair that opened the circuit leaves the loop full by the reservoir and empty where it matters. Some of these systems need a specific bleed procedure or a scan-tool-driven pump cycle to purge properly, and skipping it is how a correct repair produces the same overheating code it was meant to fix.

The tell is timing: inverter temperature or performance codes appearing shortly after any cooling system work are an incomplete bleed until proven otherwise — the corpus's unfinished-procedure argument (P0949, P2176) in hydraulic form.