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What Voids a Car Warranty

(updated October 30th, 2023)

A new car warranty promises to take care of any manufacturer defects for a period of time, but it isn't a blanket protection on everything that can go wrong with the car. A number of things can void your car's warranty, including misuse of the vehicle, an altered odometer, environmental damage, and an insurance company declaration that the vehicle is a total loss. Each reason merits discussion, which is what we'll cover in this story.

Think of your car's warranty as a contract between you and the automaker. The automaker will repair or replace certain covered items provided that you maintain the vehicle properly. But as with any contract, it can be broken if you don't hold up your end of the bargain, so it is important to know what circumstances can void your warranty.

Racing your vehicle is a surefire way to void most warranties.

Racing your vehicle is a surefire way to void most warranties.

Warranty claim denied versus a voided warranty

Not every circumstance will void your entire car warranty. In some situations, the repairs for a specific part will not be covered, but you still retain the warranty on the remainder of the vehicle.

Any time you take your car to the dealership for warranty work, the service department must file a claim with the manufacturer or warranty provider, which is how it gets paid for the work performed. If a repair isn't covered under the manufacturer's warranty, the claim will be denied and the dealer won't get paid. This could mean paying for the work out of your own pocket, and in many circumstances, a dealer will make the determination whether your car is covered before a claim is even submitted.

What voids your entire warranty?

Salvage title
If your car was in a severe accident, declared a total loss, and was issued a salvage title, the entire warranty is voided. Keep this in mind if you are looking to purchase a late-model used car from a private party or independent used car lot. Unknowingly buying a salvaged car isn't an issue with certified pre-owned vehicles or when shopping at CarMax because the dealerships are required to check on that. If you are unsure about a car's past, we suggest getting a vehicle history report.

Environmental damage
If your vehicle was damaged in a fire, flood, earthquake or any other environmental disaster, this becomes more of an issue for your insurance company because the automaker will not cover those repairs. And if the vehicle was declared a total loss as a result of the damage, the warranty would be voided.

Altered odometer
If your car's odometer has been disconnected, tampered with, or replaced, the dealer cannot determine the exact mileage. This is usually grounds for a voided warranty since it cannot verify if the vehicle is within the mileage limits. It is difficult to determine if a modern vehicle's odometer has been tampered with, but if you order a vehicle history report, it should help with flagging any inconsistencies in mileage reporting.

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What voids specific parts of your warranty?

Misuse of the vehicle
This term can be interpreted in broad ways and can include activities such as street racing, competitive driving events, overloading the vehicle, or driving off-road. Potentially, anything outside of the typical operation of the vehicle can be considered misuse. Many automakers will deny a claim for a part that failed, while some can void your entire warranty in more severe cases. This decision is typically left to the discretion of the warranty administrator. There may not be hard evidence that a vehicle went racing, but if there are signs of abuse, your warranty claim may still be denied. Data recorders in the computers of modern vehicles can give a technician specific details about the speed a car was traveling at the time of the incident and sometimes your exact location, which means it's much harder to hide the truth of a situation.

Even high-performance vehicles that seem like a natural fit for track use may not be covered if you actually take it to one and something breaks. The coverage can differ by vehicle and automaker, but some may allow track driving if the vehicle has an actual track package equipped, while other warranties will permit track driving so long as it is not an organized competitive event or a time trial. Read your warranty guide for information specific to your vehicle.

Similarly, when you have a vehicle designed to go off-road, there is still a large gray area when it comes to warranty repairs, and they may not always be covered. We experienced this firsthand, some time ago, when we took one of our long-term test cars to Death Valley, California. One of our editors was driving a 2006 Honda Ridgeline when he came across a washboard gravel road and followed it for a number of miles at speeds of 10-15 mph. On the way home, he noticed the ride was unusually bouncy and took the truck in for service. The inspection by the dealer revealed that all four struts were blown out and needed to be replaced, a service not covered under warranty on the grounds that the struts were excessively worn.

We explained to the service adviser that this 4WD truck was doing what it was designed to do and that the washboard road should not have caused the struts to fail. The Ridgeline's repairs were eventually covered under warranty as a one-time goodwill gesture, but not without our being persistent and pleading our case to Honda's customer service line and the dealership service manager.

Aftermarket parts or modifications
This aspect of warranty coverage can be related to "misuse of the vehicle" and also has a large gray area. Although some dealership service managers would have you think otherwise, simply having an aftermarket part or modifying your vehicle cannot void your entire warranty.

The argument might be that just because you have a performance part such as a cold air intake on the car, the whole vehicle warranty is void, says Loren Wong, a car enthusiast and a former warranty administrator for BMW and Acura. "That's not true," he says.

This isn't isolated to performance modifications, however. For example, if you had repairs performed with non-factory parts and it led to an issue, the damage they caused would not be covered under warranty. There is legislation that protects consumers in this scenario. The Magnuson-Moss Warranty Act of 1975 states that a dealership must prove that aftermarket equipment caused the need for repairs before it can deny warranty coverage.

When the reason for a parts failure is unclear, a dealer will usually charge you to diagnose the issue. If the aftermarket part was not properly installed or a modification led to a component failure, it is well within the dealer's right to void the warranty for that part, and you will have to pay for the repairs out of pocket. If the aftermarket parts had nothing to do with the repairs in question, you should be refunded the fee for the diagnosis.

Another issue with aftermarket performance parts is that they may advertise to dealers that you either drive the car hard or go off-roading. "Although they don't always void entire warranties," Wong added, "modifications may raise a red flag when vehicles are in for service. If consumers who mod their cars do a little research, they may find certain dealerships that are a little more 'mod-friendly' than others."

Some people are so oblivious to the needs of their vehicle, the vehicle could go months with an overdue oil change. If your car is still under warranty, avoid this at all costs. If you fail to take your vehicle in for service during its scheduled maintenance intervals, the warranty will not help you with repairing any damage to the engine.

Use of dirty or improper fluids
If your angry ex poured sugar in the gas tank or if you spaced out and put diesel fuel in your gasoline engine, any damage incurred is not covered under warranty. Always make sure you are using the correct fluids as outlined in your owner's manual.

How to prevent voided warranty issues

Read your warranty coverage booklet
Though this article has hit on some of the major issues, we still recommend reading your warranty's fine print, often bundled with your owner's manual. Find the section that says "What is not covered" or "Exclusions." Don't have your owner's manual? Many automaker websites should have them listed in their ownership section.

Service your car at regular intervals
This is a good idea in general, but for the sake of keeping your warranty intact follow the manufacturer's recommended service schedule. If you misplaced your owner's manual, you can often find it on the automaker's owner portal. Or you can always use the Edmunds maintenance calculator.

Keep all service records and receipts
It is important to keep detailed service records while the vehicle is under warranty to avoid any allegations of improper maintenance. If you have your service performed at the same dealership, it should have records on its computers in case you lose them. If you get the work done by a local repair shop, make sure it uses factory parts and get detailed copies of the work orders. For those who perform maintenance on the car themselves, it will be critical to save the receipts for the parts and fluids purchased.

Warranties are open to interpretation
If you think that a service adviser has denied your warranty claim unfairly, you can always go higher up in the management chain. After the service adviser, there's the service manager, and above them is the dealership's general manager. If your appeals fail and you feel you're in the right, contact the automaker directly or go to another dealer altogether.