Start with the records. Repair orders, warranty documents, mileage, and days out of service are more useful than general assumptions about whether a vehicle qualifies.
Blind spot monitors are meant to warn you before a lane change goes wrong. When they misread traffic, go dark without warning, or constantly flash false alerts, your daily commute can turn stressful—and unsafe. If your vehicle’s blind spot monitoring system has been in the shop again and again with no lasting fix, California’s Lemon Law may offer protections. Below, ZapLemon explains how blind spot monitor failures fit into California’s rules and what steps you can take to document the issue.
When Blind Spot Monitors Fail Under CA Lemon Law
Blind spot monitoring (BSM) systems typically rely on radar sensors, cameras, or both to detect vehicles alongside yours and illuminate a warning on your mirrors or A-pillars. Common problems include “BSM unavailable” messages, false positives that keep the light on with no car nearby, missed detections that fail to warn before a lane change, or alerts that only work intermittently—often after rain, bumper repairs, or software updates. Because drivers learn to trust these warnings, erratic behavior can undermine confidence and safety.
Under California’s Song-Beverly Consumer Warranty Act (the Lemon Law), a vehicle may qualify as a lemon if a defect covered by the manufacturer’s warranty substantially impairs the use, value, or safety of the vehicle and the manufacturer or its authorized dealer cannot repair it after a reasonable number of attempts. Safety-related electronics like BSM can meet this standard when they repeatedly malfunction. California’s “lemon law presumption” can apply within the first 18 months or 18,000 miles if: the dealer made four or more repair attempts for the same issue; or two or more attempts for an issue likely to cause death or serious injury; or the vehicle was out of service for 30 or more cumulative days for warranty repairs. Even if your situation falls outside these guidelines, you may still have rights—each case depends on its facts.
If a vehicle qualifies, potential remedies can include repurchase (buyback) or replacement, plus certain incidental costs, subject to deductions like a mileage offset. Coverage can extend to new, leased, and many used vehicles that are still under the manufacturer’s warranty. Common BSM triggers—sensor misalignment after a bumper replacement, impaired radar behind a repainted fascia, wiring faults, or software calibration issues—are the kinds of concerns that should be addressed under warranty. Strict deadlines may apply, and outcomes depend on evidence and circumstances, so consider a consultation to understand your options.
Steps to Document Repairs and Protect Your Claim
Start by keeping a simple log. Note the date, mileage, weather, road conditions, and what the blind spot monitor did or didn’t do (for example, “no alert while a vehicle was in the adjacent lane” or “constant warning with empty lane”). When safe, capture short photos or videos of dash warnings and messages like “BSM unavailable.” If the issue seems tied to conditions—heavy rain, highway speeds, night driving, or after a car wash—write that down, too.
Each time you visit a dealer, clearly describe the symptoms and ask the service advisor to write your concern exactly as you reported it, including the words “blind spot monitor” or the manufacturer’s term (e.g., “BSM,” “Blind Spot Information System,” “Side Assist”). Request copies of all repair orders, even if the technician “could not duplicate” the concern. Ask whether there are technical service bulletins (TSBs), recalls, software updates, or radar/camera alignment procedures performed, and request those details on the paperwork. If calibration was done, ask for the calibration report and software version numbers.
If the problem continues, escalate in writing. Call the manufacturer’s customer care line to open a case and note the case number in your log. Consider sending a dated letter or email to the manufacturer’s address listed in your warranty booklet to provide formal notice and request another repair attempt—this helps establish that the manufacturer had a reasonable opportunity to fix the defect. Keep all emails, texts, and voicemails with the dealer or manufacturer. Some brands offer arbitration programs; participation may be optional or required by your warranty, and timelines can be short. Before making decisions, consider speaking with a California lemon law lawyer to discuss your situation and options.
Need a case-specific review?
Use the case-review form to share the warranty, repair orders, dates, mileage, and supporting facts an attorney would need to evaluate, or call (844) 927-5366.
Attorney advertising. General information is not legal advice and does not create an attorney-client relationship. No result is promised or guaranteed.