Brand-new BMW i7 braking at ghosts — the phantom AEB fault hiding inside a software update

What the diagnosis found

The platform lined the two phantom-braking events up against the car's update history and the sensor-fusion logs: a recent over-the-air update had shifted the front radar-and-camera fusion timing, so a roadside reflection was briefly read as a stationary obstacle. The hardware was perfect; the calibration baseline had moved underneath it.

Ranked probable causes

How the system reasoned

Hard braking with no obstacle, no code, and sensors that pass on the bench rules out a simple hardware failure and points at perception, not parts. Tying both events to a recent OTA update and the fusion log exposed a timing shift that made a reflection look solid — a fault no component test would ever catch.