Ölstandsensor defekt

The sensor reporting engine oil level, faulty so the reading is unreliable. On engines with no dipstick it is the only measurement available, which raises the stakes considerably — a driver with no way to check independently has to believe it.

The asymmetry is what matters. Reading high on a low sump means no warning while the engine runs short of oil, which is the failure that destroys engines. Reading low on a correct sump causes needless topping up, and an overfilled engine aerates its oil and can damage the catalytic converter through the breather — so acting on a wrong low reading is itself harmful.

Many of these are combined level and temperature units in the sump, and they read by ultrasound or capacitance, so sludge or a coating on the sensor produces a plausible wrong value. Verify against a known quantity: drain and refill with the specified amount and see whether the reading agrees. A reading that never changes across an oil change is the clearest evidence of a failed sensor rather than a genuine level problem.