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.
Driver-assist technology—features like adaptive cruise control, lane-keep assist, automatic emergency braking, and parking assist—can make daily driving easier. But when these systems glitch, drop out without warning, or behave unpredictably, the problems can be frustrating and potentially unsafe. If you’re in California and your vehicle’s driver-assist features keep failing under warranty, you may be wondering whether the state’s lemon law could apply. This article explains how California’s lemon law treats advanced driver-assistance systems (often called ADAS) and what to document if issues persist.
Driver-Assist Failures Under California Lemon Law
California’s lemon law, formally the Song-Beverly Consumer Warranty Act, protects buyers and lessees of new vehicles that have defects covered by the manufacturer’s warranty. Even though driver-assist systems involve complex software and sensors, they’re still part of the vehicle and the warranty. If a defect in an ADAS feature substantially impairs the vehicle’s use, value, or safety—and the manufacturer can’t repair it after a reasonable number of attempts—the law may provide remedies such as repurchase or replacement. Whether a particular situation qualifies depends on the facts, the warranty, and the repair history.
What counts as a “defect” can include recurring false alarms, phantom braking, failure to maintain lane position, unreliable adaptive cruise control, or features that intermittently shut off with messages like “sensor blocked” even when conditions seem normal. Safety-related issues can be especially important. In some situations, fewer repair attempts may be required if the defect is likely to cause serious injury. Time out of service also matters; if your vehicle spends an extended number of days in the shop for warranty repairs, that can be a factor under the law.
Software-heavy vehicles add wrinkles. Over-the-air (OTA) updates, sensor recalibrations after windshield or bumper service, and technical service bulletins (TSBs) can all affect how a defect is diagnosed or repaired. An update that temporarily improves performance but the problem returns may still count as another repair attempt. Likewise, a dealership “could not duplicate” note doesn’t end the story—what’s documented, how often the issue occurs, and its impact on safe operation all contribute to the overall picture.
What to Document if Driver-Assist Glitches Persist
Start with thorough service records. Each time a driver-assist feature misbehaves, describe the symptoms in plain language when you take the vehicle in: what happened (for example, sudden braking for no object), how fast you were going, the road and weather conditions, warning lights or messages, and whether the feature was turned on according to the owner’s manual. Ask the service advisor to include your exact complaint on the repair order (RO) and request a copy of the final invoice showing what the dealer found and what steps they took.
Collect supporting evidence. Short videos of the behavior, dashcam clips, and photos of any dashboard alerts can be very helpful. Note dates, times, locations, firmware or software version numbers after updates, and any patterns (for instance, the issue happens after driving more than 30 minutes or only on certain highways). If you receive recall notices or TSB references, keep those with your records. When possible, test features under the same conditions described by the manufacturer as normal operating parameters, and record when the vehicle does not behave as expected.
Keep a timeline. Track each repair visit, days out of service, and mileage in and out. If the dealer says the condition is “normal” or “no problem found,” ask that statement to be written on the RO. Check your warranty booklet to confirm coverage for ADAS components like cameras, radar units, control modules, and sensors, and keep any communications with the manufacturer’s customer care. If problems continue despite multiple repair attempts, consider scheduling a consultation to discuss your options under California law. While this article explains general concepts, your specific situation needs personalized guidance.
Driver-assist features are supposed to increase convenience and safety, not add stress. If repeated glitches, failed updates, or long stretches in the shop are disrupting your life, you’re not alone—and you don’t have to figure it out by yourself. ZapLemon helps California consumers understand their rights under the state’s lemon law and how driver-assist defects fit into warranty protections.
This post is for informational purposes only and is not legal advice. Reading it does not create an attorney-client relationship, and results depend on the facts of each case. Laws and regulations can change, and you should consult an attorney for advice about your specific situation. Attorney advertising.
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