When your new car keeps breaking down and the dealer can’t seem to fix it, California’s “lemon law presumption” can become a powerful tool. It’s part of the state’s Song-Beverly Consumer Warranty Act and helps consumers by presuming a vehicle is a lemon when certain conditions are met. Below, ZapLemon explains what the presumption is, why it matters, and how the 18-month/18,000‑mile window works—using plain language and real-world examples.
California’s Lemon Law Presumption, Explained
California’s lemon law presumption is a legal shortcut that helps consumers prove their case. In everyday terms, if your new vehicle has a substantial defect covered by the manufacturer’s warranty and the dealer can’t fix it after a reasonable number of attempts within a specific early ownership period, the law presumes the car is a lemon. This presumption shifts the burden to the manufacturer to show the vehicle is not a lemon—saving you from having to prove every detail from scratch.
The presumption typically applies to new vehicles sold or leased in California that are covered by a manufacturer’s warranty. It’s “rebuttable,” meaning the manufacturer can try to overcome it—for example, by arguing the problem doesn’t substantially impair the vehicle’s use, value, or safety, or that the issue was caused by misuse or unauthorized modifications. Importantly, even if you don’t meet the presumption, you may still have lemon law rights; the presumption is just one path to proving your claim.
Think of a sedan that repeatedly stalls on the highway, or an SUV whose advanced driver assistance features malfunction intermittently despite multiple dealer visits. If those problems persist early in ownership and the dealer can’t fix them under warranty, the presumption may kick in. Practical steps can help: report issues promptly, insist on detailed repair orders, and keep all records. These habits protect your rights whether or not the presumption ultimately applies.
How the 18-month/18,000-mile presumption works
California law creates a special window—the first 18 months after delivery or the first 18,000 miles on the odometer, whichever comes first—where certain facts will trigger the presumption. Generally, the presumption applies if: (1) the dealer made at least two repair attempts for a defect that could cause death or serious bodily injury if the vehicle is driven; or (2) the dealer made at least four repair attempts for the same non-trivial problem; or (3) the vehicle was out of service for repairs for a total of more than 30 days. The defect must be covered by the warranty and substantially impair the vehicle’s use, value, or safety.
A “repair attempt” usually means you presented the vehicle to an authorized dealer for the same problem and asked for it to be fixed, even if no parts were replaced that day. The 30 days out of service can be non-consecutive and spread over multiple visits; getting a loaner car doesn’t erase those days. Manufacturers can try to rebut the presumption by showing, for instance, that the defect was fixed within a reasonable time, that the problem was caused by abuse or unauthorized modifications, or that the defect doesn’t substantially impair use, value, or safety.
Real-world examples help. Two unsuccessful attempts to fix a brake system defect that creates a serious safety risk may be enough for the presumption. Four unsuccessful attempts to cure a transmission shudder, persistent “check engine” warnings, recurring infotainment freezes that affect backup cameras, or chronic EV charging errors could also qualify. If your vehicle spends more than 30 days in the shop within that early window—due to parts delays or repeated diagnostics—that may trigger the presumption as well. To protect yourself, promptly schedule warranty service, document symptoms with photos or videos, request repair orders showing dates, mileage, and the dealer’s “complaint-cause-correction” notes, and consider notifying the manufacturer directly as your warranty booklet instructs.
This article is for general informational purposes only, is not legal advice, and does not create an attorney-client relationship with ZapLemon. Every situation is different, and outcomes can vary. If you have ongoing vehicle issues, the best next step is to get a personalized assessment. If you believe your vehicle may qualify as a lemon, contact ZapLemon at (310) 489-3017 or https://zaplemon.com.