Rodents Can't Get Enough of Toyota's Soy Wire Coating

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#electrical #fire #lawsuit

Don't get me wrong, the idea is great. Unfortunately rodents also think it's great because the biodegradable material is easier to chew and is an abundant nesting material.

The resulting damage can cost owners anywhere between $2,000 and $9,000. It's a huge tab and if you're thinking Toyota will pick it up, think again. Owners say Toyota denies any rodent-related warranty claims to the electrical system because its classified under "other environmental conditions" in their express warranty.

The warranty specifically excludes damage from "airborne chemicals, tree sap, road debris (including stone chips), rail dust, hail, floods, wind storms, lightning and other environmental conditions."

Wasn't it Toyota's decision to change the environment?

Bring on the Lawsuits

The soy-based wire coatings were the subject of a lawsuit that was filed back in December of 2016.

In Heidi Browder vs. Toyota Motor Corporation the plaintiff argued that Toyota knows about the problem but does nothing to help fix it.

According to the plaintiff, she learned the hard way about the soy wiring when her Avalon wouldn't start and a look under the hood showed wires chewed, so she had the car towed to a dealer. Toyota told her rodents had caused the damage and it would be no problem to repair the problems as long as she could cough up $6,000 to cover the bill.

A year later another class-action lawsuit, Roscoe v. Toyota Motor Sales USA Inc., was filed in Massachusetts.

When [a plaintiff] brought his Toyota Sequoia to the dealership for a routine oil change on December 8, 2016, he allegedly learned mice had caused extensive damage to the truck. The mice had chewed through so much of the wiring the dealership allegedly told him to immediately stop driving the truck because it could catch fire.

Both lawsuits argue that Toyota violated fraud and consumer protection laws because they know the new wiring attracts rodents, but even damaged wiring is replaced with the same problematic coating.

Ultimately, it ends up substantially increasing the costs associated with owning a Toyota.

One case dismissed, others soon to follow?

A third lawsuit was dismissed by a judge in June of 2018. The judge ruled many arguments in favor of Toyota, starting with the platintiffs using competing arguments as to why rodents eat the wires.

"Considering this considerable variance, it isn’t clear that Toyota could have specifically articulated any increased “risk” to any particular part of Plaintiffs’ vehicles because of the soy coated wiring." — Judge Andrew Guilford

Toyota argued that rodents were a problem long before switching to soy-based wiring and that one plaintiff's pointing out they had mice in their cabin is “entirely consistent with the idea that something other than insulation might explain these plaintiffs’ various rodent encounters.”

The judge agreed that the arguments are a stretch.

"Plaintiffs are, in effect, asking the Court to stretch the implied warranty of merchantability to include some promise that no external actor will later harm Plaintiffs’ vehicles. The Court declines to extend the doctrine so far."

The dismissal of Albert Heber v. Toyota Motor Sales U.S.A., et al. may be bad news for the other pending cases.

Lawsuits Regarding This Problem

Lawsuits about this problem have already been filed in court. Many times these are class-action suits that look to cover a group of owners in a particular area. Click on the lawsuit for more information and to see if you're eligible to receive any potential settlements.

  • Dismissed

    Albert Heber v. Toyota Motor Sales U.S.A., et al.

    1. Dismissed

      According to the plaintiffs, Toyota switched to soybean coated wires in various cars, vans, SUVs and trucks, but the wiring is allegedly defective because it attracts rats and other rodents. Once chewed, the damaged wiring can cause all kinds of vehicle functions to fail, allegedly creating a safety hazard.

    Class Vehicles
    • N/A
  • Roscoe v. Toyota Motor Sales USA Inc.

    1. Case Filed

      A Toyota soy wiring class-action lawsuit alleges rats, mice, squirrels and other animals are enticed to chew the wires that causes damage to all kinds of electrical components, leaving Toyota owners to pay thousands for repairs.

    Class Vehicles
    • 2011-2016 4Runner
    • 2013-2016 Avalon
    • 2012-2016 Camry Hybrid
    • 2009-2016 Camry
    • 2014-2016 Corolla
    • 2014 FJ Cruiser
    • 2009/2012/2015 Highlander
    • 2009 Matrix
    • 2010-2015 Prius
    • 2012-2015 Prius C
    • 2008-2016 Rav4
    • 2012-2015 Sequoia
    • 2011-2014 Sienna
    • 2014-2015 Tacoma
    • 2007-2016 Tundra
    • 2010-2013 Venza Ltd

Generations Where This Problem Has Been Reported

This problem has popped up in the following Toyota generations.

Most years within a generation share the same parts and manufacturing process. You can also expect them to share the same problems. So while it may not be a problem in every year yet, it's worth looking out for.

Further Reading

A timeline of stories related to this problem. We try to boil these stories down to the most important bits so you can quickly see where things stand. Interested in getting these stories in an email? Signup for free email alerts for your vehicle over at

  1. When Toyota switched away from using plastic or glass-based inulation in favor of soy, it invited in some very unwelcome Toyota loyalisits.

    According to the plaintiff, she learned the hard way about the soy wiring when her Avalon wouldn't start and a look under the hood showed wires chewed, so she had the car towed to a dealer. Toyota told her rodents had caused the damage and it would be no problem to repair the problems as long as she could cough up $6,000 to cover the bill.

    The soy-based wiring is allegedly attracting in rodents, who love to chew it up and use it for nesting material. The lawsuit, Heidi Browder vs. Toyota Motor Corporation, et al. follows a similar lawsuit filed against Honda earlier this year.

    keep reading article "Lawsuit Says Toyota’s Use of Soy-Based Wiring is Attracting Rodent Damage"

OK, Now What?

Maybe you've experienced this problem. Maybe you're concerned you will soon. Whatever the reason, here's a handful of things you can do to make sure it gets the attention it deserves.

  1. File Your Complaint is a free site dedicated to uncovering problem trends and informing owners about potential issues with their cars. Major class action law firms use this data when researching cases.

    Add a Complaint
  2. Notify CAS

    The Center for Auto Safety (CAS) is a pro-consumer organization that researches auto safety issues & often compels the US government to do the right thing through lobbying & lawsuits.

    Notify The CAS
  3. Report a Safety Concern

    The National Highway Traffic Safety Administration (NHTSA) is the US agency with the authority to conduct vehicle defect investigations & force recalls. Their focus is on safety-related issues.

    Report to NHTSA