Warning lights that turn on, then magically disappear after a restart or software update, are frustrating—and confusing. If you’re in California and your car keeps resetting a check engine, airbag, brake, hybrid/EV battery, or ADAS sensor light, you may wonder whether the California Lemon Law can still apply. The short answer: a reset light doesn’t erase a defect, and intermittent problems can still be covered. Below, we explain how California’s law views “on-and-off” warning lights and how to document your experience so you can make informed next steps.
California Lemon Law: Warning Light Keeps Resetting
California’s Song-Beverly Consumer Warranty Act—often called the California Lemon Law—protects buyers and lessees of new and many used vehicles that come with a manufacturer’s warranty. If a covered defect 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, the consumer may have remedies. A warning light that resets doesn’t wipe away the defect; the law looks at the pattern of problems and repair history.
Intermittent or “no trouble found” situations are common with electronics-heavy cars. Check engine lights that clear after driving, recurring ADAS calibration alerts, sporadic airbag lights, or EV battery and charging warnings may come and go—especially after a dealer clears codes or software is updated. What matters is whether the defect persists or recurs, how often you sought repairs, and how long the vehicle was out of service. Safety-related defects may require fewer attempts to meet the “reasonable number” threshold than non-safety issues.
California also includes a helpful presumption (often called the Tanner presumption) during the first 18 months or 18,000 miles from delivery: the law presumes you’ve given a reasonable number of repair opportunities if the same issue has (1) two or more attempts for a defect likely to cause death or serious injury, (2) four or more attempts for the same problem, or (3) the car has been out of service for repairs for a total of 30 or more days. This presumption is not required to pursue a claim—it simply makes the consumer’s burden easier in some cases. Lemon Law claims can also involve used vehicles that are still covered by the manufacturer’s warranty. Every situation is fact-specific, so a consultation is important.
How to Document Resets, Repairs, and Repeat Issues
Start a simple log. When a warning light appears, safely take a photo or short video showing the dashboard, the specific icon, the mileage, and the date/time (phone timestamps help). Note driving conditions—speed, temperature, battery level, fuel level, whether features like ACC or lane-keep were active, and any noises or drivability symptoms. If it’s safe and you have one, an OBD-II scan screenshot of stored codes can be useful—but don’t modify or clear anything yourself, and don’t drive an unsafe vehicle just to capture data.
Open a repair order every time. At the dealership, clearly describe the symptoms in your own words and ask that your exact complaint be written on the repair order. Ask the dealer to scan for codes before clearing anything and request copies of all repair orders and final invoices, including “could not duplicate” results. Make sure each document shows the dates in/out, odometer in/out, the technician’s cause and correction notes, parts replaced, and software versions updated. Keep everything together—R/Os, TSB references, recall paperwork, and tow or rental records.
Track time out of service and recurrence. Keep a calendar tally of days the vehicle is at the dealership, including wait times for parts. Save emails or texts with the service advisor or manufacturer, loaner or rental agreements, and any over-the-air update notices. If the light returns after a software flash or module replacement, note the date and mileage and take fresh photos. Consistency helps: describe the issue the same way across visits. If the problem affects safety systems (airbags, brakes, steering, ADAS), note that clearly. When you’re ready to explore your options, consider contacting a California Lemon Law attorney to review your documentation.
A warning light that keeps resetting can still signal a real defect—and repeated trips to the dealer, “no problem found” notes, or temporary fixes do not bar you from protection under California’s Lemon Law. The key is a clear record of what you experienced, each repair opportunity, and how the issue impacts use, value, or safety. Because every case depends on its specific facts and warranty history, getting tailored guidance matters.
This article is for informational purposes only, is not legal advice, and does not create an attorney-client relationship. If you believe your vehicle may qualify as a lemon, contact ZapLemon for a consultation at www.zaplemon.com.