California Lemon Law for Collision Avoidance Defects

Collision avoidance technology—features like automatic emergency braking, forward collision warning, and lane-keeping assistance—can make driving safer, but when these systems glitch, misfire, or fail, they can put you and your passengers at risk. If your vehicle’s collision avoidance system has repeated problems that the dealer can’t fix under warranty, California’s Lemon Law may offer relief. Below, ZapLemon explains how these defects fit into the law, what to document, and when to reach out for help. This article is for general information only and isn’t legal advice.

Collision Avoidance Defects Under CA Lemon Law

Collision avoidance systems are part of a vehicle’s advanced driver-assistance suite (often called ADAS). Common issues include “phantom braking” (the car brakes for no reason), delayed or no braking when an obstacle is present, false collision alerts, lane-keeping that pulls the car out of its lane, or systems that frequently disable themselves due to sensor faults. These problems can stem from miscalibrated cameras, radar obstructions, software bugs, faulty control modules, or inadequate updates after a windshield or bumper replacement. When these defects persist, they can substantially affect the vehicle’s use, value, or safety—key factors under California law.

California’s Lemon Law (the Song-Beverly Consumer Warranty Act) generally applies when a manufacturer cannot repair a defect covered by the warranty after a reasonable number of attempts. For serious safety defects—issues that could cause serious injury or death if the vehicle is driven—the “reasonable number” can be fewer attempts than for non-safety issues. There’s also a legal “presumption” that may apply within the first 18 months or 18,000 miles after delivery: for example, if the car has two or more repair attempts for a serious safety defect, four or more for a non-safety defect, or is out of service for 30 or more cumulative days. Even if you’re outside those benchmarks, you may still have rights if the defect occurred under warranty.

Collision avoidance defects often qualify as safety-related because they directly affect a driver’s ability to avoid crashes. A vehicle that suddenly slams on the brakes without cause, or fails to brake when it should, poses obvious risks. If the dealership keeps attempting software updates, sensor calibrations, or module replacements without resolving the problem—or if you repeatedly hear “no trouble found” while the issue persists—those visits may count as repair attempts. The details matter, which is why thorough documentation is essential and a consultation can help you understand your options.

What to Document and When to Seek Help at ZapLemon

Start a simple paper trail. Each time the issue occurs, note the date, mileage, speed, weather, road type, and what the system did or failed to do (for example, “phantom braking at 65 mph in clear weather,” “AEB unavailable in light rain,” or “Lane-keep pulled left on straight highway”). Capture short, safe videos if possible—dashcam clips and smartphone recordings can be helpful. Keep all dealer repair orders and invoices, making sure they accurately describe your complaint, the technician’s findings (including “could not duplicate”), parts replaced, software versions, calibrations performed, and the number of days your vehicle stayed at the shop.

Ask the service advisor to include specifics, such as diagnostic trouble codes, ADAS calibration printouts, and references to technical service bulletins or recalls. If the dealer says the system is “normal,” request a test drive with a technician to reproduce the behavior. After windshield or bumper work, confirm that camera and radar calibrations were completed and documented. Save recall notices, over-the-air update notes, and any messages from the manufacturer’s customer care team. These records help establish patterns, timelines, and whether the manufacturer had a fair opportunity to fix the defect.

Consider contacting ZapLemon if you’ve made repeated warranty visits for the same collision avoidance problem, the vehicle has been out of service for many days, the issue feels dangerous, or you’re getting conflicting explanations. We can discuss general timelines, what counts as a repair attempt, and practical next steps like sending written notice to the manufacturer. A consultation is the best way to understand how the law may apply to your situation; outcomes vary based on facts, documentation, and warranty terms. We don’t guarantee results, but we can help you evaluate your options and chart a plan.