What is blind spot monitoring?
Reviewed by the Skyview Auto Glass technical team — NWRD-, ASE- and DINITROL-trained technicians · Updated November 2026
Quick answer
Blind spot monitoring warns you when a vehicle is in the lane beside and behind you, where the mirrors cannot see. It uses rear-corner radar sensors in the rear bumper, not the windshield camera. A light in the mirror or door panel glows, and some systems add a chime when you signal into a car.
How blind spot monitoring works
Two radar sensors, one in each rear corner of the bumper, sweep the lanes beside and behind the vehicle. When a car enters the blind zone, the system lights an icon in the side mirror or the door panel. If you switch on the turn signal while a car is there, many systems add a chime or a steering pulse to warn you.
The sensors live in the rear bumper, not the windshield. That means a windshield replacement does not affect blind spot monitoring, and the feature does not need recalibration when the glass is changed. See our guide on which safety features use the windshield camera to tell the two apart.
Does a windshield replacement affect blind spot monitoring?
No. Blind spot monitoring uses rear-corner radar in the bumper, not the forward camera behind the glass. A windshield replacement does not touch those sensors, and the feature does not need recalibration when the glass is changed.
Where blind spot sensors are located
The sensor location tells you which glass work, if any, affects the feature.
| Sensor | Location | Affected by a windshield replacement? |
|---|---|---|
| Blind spot radar | Rear bumper corners | No |
| Forward camera | Behind the windshield | Yes — needs recalibration |
| Rear camera | Liftgate or trunk | Only if back glass is replaced |
Blind spot monitoring is one of the few driver-assist features that does not depend on the windshield camera.
More questions about blind spot monitoring
How does blind spot monitoring work?
Radar sensors in the rear bumper corners watch the lanes beside and behind you. When a car is in the blind zone, a mirror or door icon lights, and a chime may sound when you signal into it.
Where are blind spot sensors located?
In the rear bumper corners, not the windshield. They use rear-corner radar, so a windshield replacement does not affect them.
Does a windshield replacement affect blind spot monitoring?
No. The feature uses rear-bumper radar, not the forward camera behind the glass, so changing the windshield does not touch it and no recalibration is needed.
Related guides
More in ADAS cameras and calibration
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