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 monitoring is meant to be an extra set of eyes on the road. When it chirps at nothing, fails to warn of a car next to you, or lights up randomly, it stops being helpful and starts becoming a safety risk. If your vehicle’s system has been in the shop repeatedly, you may be wondering whether California’s Lemon Law can help. Below, ZapLemon explains how faulty blind spot monitors fit into Lemon Law CA and what you can do to document the problem—without offering legal advice—so you can make informed next steps.
Faulty Blind Spot Monitors and California Lemon Law
Blind spot monitoring (often called BSM or BLIS) uses radar sensors or cameras in the rear corners of a vehicle to detect cars in adjacent lanes. Defects can show up as false alerts, no alerts at all, intermittent warnings, or messages like “Blind Spot System Unavailable.” Drivers commonly report problems after minor bumper repairs, in heavy rain, during lane changes, or at highway speeds. Because BSM is a safety feature tied to lane-change decisions, persistent malfunctions can meaningfully affect the safety and value of the vehicle.
In California, the Song-Beverly Consumer Warranty Act—often referred to as the California Lemon Law—may apply when a vehicle has a defect covered by the manufacturer’s warranty that the dealer cannot fix after a reasonable number of attempts, or when the vehicle is out of service for an extended period. The law looks at whether the defect substantially impairs the use, value, or safety of the vehicle. Ongoing blind spot monitoring failures can meet that threshold when they persist despite repairs, especially when the issue started during the warranty period and the dealer has had multiple chances to correct it.
Manufacturers often try software updates, sensor replacements, bumper cover alignment, or calibration procedures to address BSM complaints. Some vehicles may have technical service bulletins (TSBs) or recalls related to radar modules, wiring harnesses, or camera calibration. Outcomes under the Lemon Law can include repurchase, replacement, or a cash settlement, depending on the facts, but no result is guaranteed. Deadlines and technical details matter, including when the problem first appeared and how many days the vehicle was in the shop. A consultation is the best way to evaluate options based on your situation.
How to Document Repairs and Protect Your Rights
Good documentation can make a big difference. When you schedule service, describe the symptoms clearly: for example, “Blind spot monitor fails to warn of vehicles on the left at 65 mph,” or “Right-side indicator illuminates with no vehicle present in light rain.” Note the conditions (speed, weather, road type), save photos or short videos of warning lights or messages, and keep a log with dates and mileage. Ask the service advisor to write your exact complaint on the repair order, not just “check ADAS.”
At pickup, review the repair invoice before you leave. Make sure it shows the in/out mileage, dates, the technician’s findings, and the exact repairs performed—software versions updated, calibrations completed, sensors or control modules replaced, and any TSB numbers referenced. Keep copies of all invoices, even if the dealer says “operating as designed.” Track days your car is out of service, and save receipts for rentals, towing, or rideshare if applicable. Check for recalls and TSBs on the NHTSA website and your manufacturer’s owner portal so you know what’s been published about your model.
If the problem continues after multiple visits or your vehicle has been in the shop for an extended period, it may be time to explore your legal options. Continue taking the car to an authorized dealer so repairs remain documented under the manufacturer’s warranty. Avoid aftermarket modifications to sensors or bumpers that could complicate diagnostics. Deadlines can apply under California law, and every case is unique, so consider speaking with a professional who can review your records and advise you on next steps. ZapLemon can evaluate whether your faulty blind spot monitoring might qualify under Lemon Law CA.
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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.