Understanding the terms and conditions of your car warranty is essential to vehicle ownership. Whether you are buying a new or used vehicle or have just purchased a separate extended warranty, knowing what your plan covers can save you hundreds or thousands of dollars over the vehicle’s life span. To protect your vehicle warranty, you need to know what actions void it so you can properly maintain your vehicle and protect your bank account. Learn more about what voids a car warranty.
What Is a Car Warranty?
A car warranty, also called a vehicle manufacturer’s warranty, comes with a new car or certified pre-owned vehicle. A warranty protects new owners from hefty repairs caused by factory or manufacturer defects and faulty parts. An extended car warranty is a vehicle service contract that continues protections on the vehicle once the manufacturer’s warranty has expired. Vehicle owners can purchase these warranties from the dealership or a third-party provider. However, both the manufacturer’s and extended warranties have items that can void the agreement.
What Voids a Car Warranty?
A manufacturer warranty is commonly referred to as bumper-to-bumper coverage and is a contract between the vehicle owner and the automaker. The contract stipulates that the automaker will be responsible for any applicable repairs if the owner has properly maintained the vehicle. A warranty isn’t ironclad, and it’s important to know what circumstances will void your warranty. Typical items that can void a car warranty include the following:
Vehicle Misuse
Vehicles serve a purpose — typically day-to-day driving. Reckless driving is evident in the wear and tear of a vehicle’s internal parts. Even if you have a speedster or a rugged four-wheeler, you might be in danger of voiding your warranty if you use your vehicle for anything other than day-to-day driving.
Salvage Title
A vehicle receives a salvage title when it has been in an accident and sustained so much damage that it is considered a total loss by an insurance company. Buying a salvaged car is not a worry with certified pre-owned vehicles. If you are purchasing a used vehicle from a third party or private sale, consider getting a vehicle history report before you commit to the purchase. Once the vehicle has been totaled and receives a salvage title, the manufacturer will no longer warranty any problems or repairs.
Failure to Adhere to the Routine Maintenance Schedule
A vehicle owner’s manual typically details the suggested schedule for routine maintenance on the vehicle. This maintenance includes services like tire rotations, fluid level checks, and oil changes. Failure to follow this schedule can break the warranty agreement. When getting your vehicle serviced according to the manufacturer’s recommendations, keep invoices, receipts, and any documentation that proves you have maintained the suggested schedule of services. If you need to make a claim on your warranty, you may need to produce these documents.
Environmental Damage
If environmental forces damage your vehicle, the warranty will get voided. These environmental forces include natural disasters such as floods, fires, or severe weather events such as thunderstorms.
Altered Odometer
An odometer is a device that measures the distance traveled in a vehicle. A dealership service department can’t determine the exact mileage if your car’s odometer has been disconnected, altered, changed, or shown signs of tampering. An altered odometer can produce a reason to void a warranty.
Dirty or Incorrect Fluids
If tampering has occurred with your vehicle’s fluids, your vehicle warranty could be subject to termination. This tampering includes actions such as vandals pouring sugar in your gas tank to you accidentally filling your tank with diesel when the vehicle requires regular gas. Using an oil that is too viscous or not following the manufacturer’s recommendations for maintaining your vehicle’s engine coolant are also ways to void your car warranty. Read your owner’s manual for the factory-recommended fluids to use with your vehicle’s particular make, model, and year.
After-Market Modifications and Parts
Although having an after-market part on your vehicle is not immediate grounds to void your warranty, it is wise to be judicious in your choices. Thanks to the Magnuson-Moss Warranty Act of 1975, a dealer must prove that the after-market part caused a malfunction or a need for repairs. If it is unclear what is causing the malfunction in the vehicle, the owner usually has to pay for a diagnosis.
Suppose the dealership finds the damage is due to an after-market modification or an after-market part installed incorrectly. In that case, the dealer may void the warranty and require the owner to pay out-of-pocket costs for the repairs. Modifications can alert service teams and cause them to suspect an owner is racing, off-roading, or misusing a vehicle.
Reasons a Warranty Claim May Get Denied
Some reasons a warranty claim may be denied include but are not limited to:
- Damage caused by after-market parts
- Damage due to modification
- Damage from repairs at a nonapproved repair facility
- Damage from neglect or lack of routine maintenance
- Failure to produce documents showing your maintenance schedule
Tips to Help Drivers Avoid Warranty Issues
Consider these tips to properly maintain your vehicle and protect your warranty in case you need to place a claim.
- Check with the dealership’s service department before modifying your vehicle. Services that may protect your vehicle, such as undercoating, can void some or all of your vehicle warranty.
- Avoid vehicle misuse through racing and off-roading until the warranty has expired.
- Check with the dealership or manufacturer if your vehicle has been totaled or sustained substantial damage in a car accident.
- Make sure you read your entire vehicle’s warranty or the third-party warranty provider plan. Note the fine print. Locate the section that details “what is not covered” to understand which repairs you will pay for out of pocket.
Responsible vehicle ownership can be a gratifying experience and help prolong the life of your vehicle while reducing your overall cost of ownership. Educating yourself and learning about your warranty and what voids a car warranty is the best way to ensure your coverage continues for as long as possible.

At FIXD, our mission is to make car ownership as simple, easy, and affordable as possible. Our research team utilizes the latest automotive data and insights to create tools and resources that help drivers get peace of mind and save money over the life of their car.