Most newer vehicles carry a camera tucked behind the rearview mirror. It watches lane lines, traffic, and obstacles, and it feeds the systems that nudge your steering or hit the brakes for you. That camera aims through the windshield — which makes the windshield part of the optical system.
Why Replacement Disturbs It
Swap the glass and the camera's view shifts by some fraction of a degree. That sounds like nothing. Projected a hundred yards down the road, it's the difference between the system seeing you centered in the lane and seeing you drifting toward the shoulder. The safety features keep "working" — they just work off a wrong picture.How Recalibration Puts It Right
Depending on the manufacturer, recalibration is done one of two ways, sometimes both:- Static: the vehicle faces a printed target at an exact measured distance and the computer realigns the camera against it.
- Dynamic: a diagnostic tool rides along while the vehicle is driven on well-marked roads until the system confirms alignment.