After 18 months or 18,000 miles, you lose a shortcut for proving your case, not the case itself. The repair history then carries more of the weight.
What the 18-month rule actually is
Civil Code § 1793.22(b) creates a presumption that a manufacturer had a reasonable number of repair attempts when certain things happen within 18 months of delivery or 18,000 miles, whichever comes first. Examples are four or more repair attempts for the same problem, two or more for a serious safety defect, or more than 30 calendar days out of service for repairs. Some conditions apply, such as direct notice to the manufacturer in certain cases.
A presumption is a starting point in proving a claim. It is not a deadline for having one.
What still applies after the window
The core duty in Civil Code § 1793.2(d)(2) is not limited to 18 months: if the manufacturer or its repair facilities cannot fix a warranty defect after a reasonable number of attempts, replacement or restitution may be required for a qualifying new vehicle. A problem that starts or keeps returning later in the warranty period can still be part of a claim.
Without the presumption, the question is whether the number of attempts and the time out of service were reasonable for that problem. Records of every visit matter more.
The 30-day rule
Within the 18-month, 18,000-mile window, more than 30 calendar days out of service for repairs, added up across visits, is one of the ways to trigger the presumption. After the window, days in the shop still count as evidence of how the problem affected you, but they are weighed with everything else.
What to gather
- Delivery date and odometer reading at delivery.
- Every repair order for the problem, including visits where the shop found nothing wrong.
- The dates the vehicle was dropped off and picked up each time.
- Warranty booklet showing coverage periods and mileage limits.
- Any written notice you sent to the manufacturer and its reply.