Blind spot monitors are meant to be a second set of eyes, warning you about cars hiding in the lane next to you. When they fail—by staying dark, throwing false alarms, or working only sometimes—the risk and frustration add up quickly. If these problems continue while your vehicle is under warranty, California’s lemon law may offer options. This article explains how blind spot monitor defects fit under California law and what to document before you contact ZapLemon for a consultation.
Blind Spot Monitor Defects and California Lemon Law
Blind spot monitors typically use radar, ultrasonic sensors, or cameras to detect vehicles in adjacent lanes and trigger a light or chime. Common problems include no alert when a vehicle is present, constant or random false alerts, sensors that fail in rain or on highways, or systems that shut off with a “temporarily unavailable” message. These issues can stem from faulty sensors, misaligned brackets, wiring faults, software glitches, or damaged bumper covers affecting radar performance.
Under California’s Song-Beverly Consumer Warranty Act (the California Lemon Law), a vehicle may qualify as a “lemon” if a defect covered by the manufacturer’s warranty substantially impairs the vehicle’s use, value, or safety and the manufacturer (through its dealers) can’t fix it after a reasonable number of attempts. Safety-related driver assistance features—like blind spot monitoring—can meet that standard when failures create real-world risks, such as missed warnings during lane changes. Coverage can extend to many new vehicles and, in some cases, certain used or certified pre-owned vehicles that are still under the manufacturer’s warranty.
California also has a “lemon law presumption” that can help consumers in specific circumstances, generally within the first 18 months or 18,000 miles, whichever comes first. While every case is different, the presumption can apply if, for example, there are multiple repair attempts for the same defect, two or more attempts for a defect likely to cause serious injury or death, or the vehicle is out of service for 30 or more cumulative days for warranty repairs. These are not strict requirements for every claim, and outcomes depend on the facts. Remedies under the law can include repurchase, replacement, or other relief, but this article is for informational purposes only and makes no guarantees.
What to Document and When to Call ZapLemon for Help
Good records are key. Save every repair order and invoice from the dealership, even if the service was “no problem found.” Make sure your repair orders accurately describe your blind spot monitor symptoms—note whether the issue is intermittent, weather-related, or linked to highway speeds. Keep dates, mileage in/out, days the vehicle was at the shop, loaner or rental records, and any case numbers from the manufacturer.
If it’s safe to do so, consider recording short videos showing the problem (for instance, a car in the blind spot with no warning light), along with the date and conditions. Check for technical service bulletins (TSBs) or recalls on your vehicle, and keep copies of any software update notes. Review your warranty booklet so you know the coverage period and what systems are included. Consistent, clear documentation can help a technician diagnose the defect and can be important if you later explore your legal options.
Consider calling ZapLemon if your blind spot monitor defect keeps returning after multiple warranty repair attempts, your vehicle has spent significant time in the shop, or the dealer says “operating as designed” despite ongoing problems. An early consultation can help you understand the process and timelines under California law, including steps to keep your documentation organized. Speaking with a lawyer is the best way to get advice on your specific situation; this article is not legal advice and does not create an attorney-client relationship. To discuss your circumstances, contact ZapLemon for a consultation.
This article is provided for general informational purposes and is not legal advice. Reading it does not create an attorney-client relationship with ZapLemon. Legal outcomes depend on the facts of each case, and you should consult an attorney for guidance tailored to you. If you believe your vehicle may qualify as a lemon, contact ZapLemon at (310) 489-3017 or https://zaplemon.com.