ADAS Defects: Phantom Braking, Lane Keep Failures, and the Florida Lemon Law

Advanced driver assistance systems are supposed to protect you. Automatic emergency braking, adaptive cruise control, lane keep assist, and blind spot monitoring all offer an extra set of eyes.

But when those systems misfire, they become the hazard. A car that slams its own brakes on an empty highway, or yanks the wheel toward a lane line that is not there, is scarier than a car with no assistance at all.

Common ADAS defects Florida drivers report

• Phantom braking, where automatic emergency braking activates with nothing ahead
• False forward collision warnings that startle the driver
• Lane keep assist that tugs the wheel at the wrong time or shuts off randomly
• Adaptive cruise control that drops out or brakes erratically
• Blind spot monitors that miss vehicles or alert constantly
• Cameras and radar units that fault out in rain, which Florida has plenty of

These systems rely on cameras, radar, software, and calibration. A defect in any one layer can produce dangerous behavior that is hard for a dealer to reproduce in the service lane.

Why ADAS defects fit the Lemon Law so well

Florida's Lemon Law, Chapter 681 of the Florida Statutes, covers defects that substantially impair the use, value, or safety of a new or demonstrator vehicle. ADAS defects are safety defects almost by definition. A car that brakes hard without warning invites a rear-end collision. A system you have learned to distrust, or turned off entirely, has also impaired the value of what you paid for.

The defect must first be reported during the Lemon Law Rights Period, the 24 months after the car was delivered to you. From there, the law presumes the manufacturer had a reasonable opportunity to repair when:

1. The same defect has been subject to repair three or more times, or
2. The car has been out of service for repair for 15 or more cumulative days.

Camera replacements, radar recalibrations, and software updates all count as repair attempts when you reported the same underlying problem. Our guide to the three repair attempts rule explains the counting in detail.

Documenting a system that misbehaves at random

ADAS faults are the classic intermittent defect. Here is how to make them visible:

1. Write down every event immediately: date, time, road, speed, weather, and what the car did.
2. Photograph any warning messages, like "front camera unavailable" or "AEB fault."
3. If your car has a dashcam, save the clip. Footage of phantom braking is hard for anyone to argue with.
4. Report every event to the dealer, even if you do not leave the car, and insist your description goes on a repair order.
5. Ask whether the manufacturer has technical service bulletins for your system. TSBs showing a known issue are valuable, and our post on technical service bulletins explains how to use them.

Dealers often respond with "system operating as designed." That visit still counts as a repair attempt if you reported the defect. Get the dealer's response in writing, because "operating as designed" looks weak next to your dashcam clip. For more tactics, see proving intermittent defects.

One detail worth checking: many ADAS cameras sit behind the windshield and need recalibration after glass work, alignments, or even some suspension repairs. If your problems started right after a dealer repair, say so on the repair order. A system the dealer cannot keep calibrated is still a defect under the statute, and every recalibration visit joins your repair attempt count.

From notification to arbitration

After the third attempt or 15 cumulative days out of service, send the manufacturer a written Motor Vehicle Defect Notification by registered or express mail. The manufacturer then has 10 days to direct you to a repair facility for one final attempt and up to 10 days after delivery of the car to fix it.

If the system still misbehaves, you can request a hearing before the Florida New Motor Vehicle Arbitration Board. Remedies include a replacement vehicle or a repurchase. A repurchase refund includes the purchase price, collateral charges, and finance charges, reduced by a statutory mileage offset.

Turning the system off is not a fix

Some service advisors suggest simply disabling lane keep or cruise features. You paid for a car with working safety systems. Disabling a defective feature does not cure the defect, and you should note in writing that you declined to accept that as a repair. The substantial impairment to value remains when a safety feature you bought cannot be trusted or used.

Parts delays and loaner cars while ADAS repairs drag

Cameras, radar modules, and the calibration targets dealers need for them are not always on the shelf. A backordered sensor can keep a car in the service lane for weeks, and every one of those days counts toward the 15 cumulative out-of-service days that trigger the statute's presumption. Accepting a loaner does not pause that count, so take the loaner and keep the paperwork. Save the repair order showing the drop-off date, the invoice showing the pickup date, and any text or email about parts on order. If the shop holds the car while waiting on a calibration appointment, those days belong in your total too.

Think your car qualifies?

If your car's driver assistance systems keep misfiring after multiple visits, take our free 2-minute case check or call Recalde Lemon Law at (305) 792-9100. We can review your repair history against the Chapter 681 requirements and help you plan the next step.