When Modern Vehicles Fail in New Ways
Today’s vehicles rely on advanced software, sensors, and battery systems as much as traditional mechanical components. For California drivers, this shift has created a new category of Lemon Law claims that extends beyond engines or transmissions.
At Manning Law, APC, we represent consumers dealing with persistent vehicle defects tied to software failures, electric vehicle systems, and unresolved safety concerns that remain after repeated dealership visits.
California’s Lemon Law is designed to protect buyers and lessees when a vehicle cannot be repaired within a reasonable number of attempts. As vehicle technology evolves, so does the way these claims are evaluated, documented, and pursued.
Lemon Law & California’s Presumption Rules
California law provides statutory presumptions that can simplify Lemon Law claims when specific thresholds are met. These protections apply to mechanical, electrical, and software-driven defects alike.
Courts and manufacturers often evaluate:
- The number of repair attempts made for the same defect during the warranty period.
- Whether the defect substantially impairs the vehicle’s use, value, or safety.
- The amount of time the vehicle has been out of service, particularly during the first 18 months or 18,000 miles.
These presumptions are especially relevant for software-related defects, where dealerships may repeatedly mark issues as resolved without delivering a lasting fix.
What is the Tanner Presumption?
Under California’s Lemon Law framework, the Tanner Presumption functions as an evidentiary standard embedded in the Song-Beverly Consumer Warranty Act. It does not stand alone as a separate claim, but it helps clarify when a vehicle is legally presumed defective by focusing on the manufacturer’s opportunity and failure to correct ongoing problems.
At its core, the Tanner Presumption recognizes that consumers should not be required to endlessly return a vehicle for the same unresolved defect. When certain statutory conditions are met, the law presumes that the manufacturer has had a reasonable opportunity to repair the problem and failed to do so. This presumption can play a critical role in lemon law disputes by shifting the focus from whether the defect exists to whether the manufacturer can rebut the presumption.
When the Tanner Presumption Applies
The Tanner Presumption generally applies when a defect arises within the earlier of 18 months from delivery or 18,000 miles of use. During this period, repair attempts and time out of service are closely evaluated to determine whether the statutory thresholds have been met.
Under California Civil Code § 1793.2 et seq., the presumption may arise when:
- A manufacturer or its authorized dealer has made two or more repair attempts to fix a defect that poses a serious risk to vehicle safety, such as braking, steering, or advanced driver-assistance system failures, and the defect remains unresolved.
- The vehicle has undergone multiple repair attempts for the same non-safety-related defect, which continues to impair its use or value substantially.
- The vehicle has been out of service for warranty repairs for a cumulative total of 30 or more days, regardless of whether those days were consecutive or involved different repair issues.
Once these conditions are met, the burden may shift to the manufacturer to demonstrate that the vehicle does not qualify as a lemon under the statute. This shift can significantly affect how a claim is evaluated and negotiated.
Why the Tanner Presumption Matters for Modern Vehicles
The Tanner Presumption is particularly relevant in cases involving today’s technology-driven vehicles. Software defects, electronic safety system failures, and electric vehicle performance issues often present as intermittent problems that are difficult to resolve permanently. Dealerships may repeatedly attempt software resets, apply over-the-air updates, or document repairs as completed even though the underlying issue persists.
In these situations, the Tanner Presumption helps prevent manufacturers from relying on temporary fixes or repeated service visits to avoid accountability. It emphasizes the consumer’s repair history rather than requiring proof of a single catastrophic failure.
Understanding how the Tanner Presumption applies requires careful review of repair orders, service timelines, warranty coverage, and diagnostic notes. When properly evaluated, it can provide a structured legal framework for determining whether a vehicle meets California’s lemon law criteria, even when defects involve complex or evolving automotive technology.
Software Failures, OTA Updates & Emerging Lemon Law Claims
Many modern vehicles rely on over-the-air updates to correct defects. While convenient in theory, these updates do not always resolve underlying problems and may introduce new issues.
Common software-related Lemon Law concerns include:
- Ghost braking and driver-assistance errors. This includes unexpected braking events triggered by sensor or software misinterpretation that raise safety concerns.
- Infotainment and control system failures. This includes repeated malfunctions involving navigation, cameras, climate controls, or digital displays.
- OTA updates that fail to correct known defects. This includes software patches that acknowledge issues but do not provide a durable solution.
When software-related problems persist despite repeated updates or service visits, California’s Lemon Law may still apply even when no physical part replacement occurs.
Electric Vehicles, Battery Systems & Long-Term Reliability
Electric vehicles introduce additional considerations into Lemon Law claims, particularly when defects affect charging, range, or thermal regulation. Battery and software integration problems can significantly impact daily usability and long-term value.
EV-related issues that may support a claim include:
- Accelerated battery degradation. This includes range loss that interferes with routine commuting or charging reliability.
- Thermal management system failures. This includes cooling issues that trigger warnings, limit performance, or affect charging speed.
- Charging compatibility and software integration issues. This includes persistent failures between vehicle systems and charging infrastructure.
Establishing these claims often involves careful analysis of service records, diagnostic data, and manufacturer communications.
Newport Beach Dealership Repairs & Lemon Law Patterns
Many Lemon Law cases are shaped by how dealerships document and attempt repairs. Newport Beach serves as a regional hub for several high-volume dealerships, where consumers often experience repeated visits for the same unresolved defect.
Issues that frequently arise at the dealership level include:
- Repair orders that reference software resets or updates without addressing root causes.
- Extended delays while waiting for manufacturer guidance or revised firmware.
- Defects marked as corrected that reappear shortly after vehicle pickup.
When a vehicle purchased or serviced in Newport Beach continues to exhibit the same defect, the service history from that dealership can play a key role in evaluating whether Lemon Law presumptions apply.
How Manning Law, APC Handles Lemon Law Claims in Newport Beach
Lemon Law cases require detailed evidence review, technical understanding, and strategic advocacy. Our firm approaches these claims with a focus on modern vehicle systems and statutory compliance.
Our work often includes:
- Reviewing warranty terms, repair histories, and service documentation.
- Analyzing software updates, diagnostic records, and EV performance data.
- Evaluating whether the Tanner Presumption or other statutory thresholds apply.
- Pursuing remedies available under California law, including repurchase or replacement when appropriate.
Talk With a Lemon Law Attorney
If your vehicle continues to suffer from unresolved defects, repeated software failures, or EV system problems after service appointments or software updates, Lemon Law protections may provide a path forward. Manning Law, APC represents California consumers in Newport Beach and across Orange County dealing with vehicles that do not conform to warranty obligations. Let our legal team assist you today.
Call (800) 783-5006 or contact us online to discuss your situation and learn how we can assist with your claim.