(NAPSI)—In  addition to the gleaming paint job and that special smell, there’s something else that the owner of a new car gets to enjoy—the warranty.

A warranty is a promise, often made by a manufacturer, to stand behind its product or to fix certain defects or malfunctions over a period of time. The warranty pays for any covered repairs or part replacements during the warranty period. But can a dealer void your car’s warranty if you have someone else do routine maintenance on the vehicle? The answer is no, and the Federal Trade Commission, the nation’s consumer protection agency, wants to make sure consumers know it.

Under federal law, it’s illegal for manufacturers or dealers to refuse to honor a warranty or to deny coverage simply because someone other than the dealer did work on the car. And dealers must be able to demonstrate that improper repair caused the damage that they refuse to cover.

The FTC offers these and other tips for American consumers to help them make smart decisions and get the most out of their auto warranties. For example, if an independent mechanic improperly replaced a belt and the engine is damaged as a result, a manufacturer or dealer may only deny responsibility for fixing the engine under the warranty after demonstrating that the improper belt replacement—rather than some other defect—caused the engine damage. However, the warranty would still be in effect for other parts of the car.

The same is true of “aftermarket” parts made by a company other than the vehicle manufacturer or the original equipment manufacturer: The manufacturer may not deny warranty coverage unless it can show that the aftermarket equipment caused the need for repairs.

Other tips from the FTC include:

• Read the warranty that came with the car, or check the “Owners” section of the manufacturer’s website.

• Be aware of when the warranty period ends, and get any problems that arise checked out beforehand.

• Service the car at regular intervals, following the manufacturer’s recommended service schedule.

• Keep all service records and receipts, regardless of who performs the service. This includes oil changes, tire rotations, belt replacement, new brake pads, and inspections. These receipts can be used to prove that the vehicle was properly maintained.

• Complain. If you think a dealer’s service advisor denied your warranty claim unfairly, ask to speak with a supervisor. If you still aren’t satisfied, contact the manufacturer or go to another dealer. You might also want to complain to your state Attorney General, local consumer protection agency and Better Business Bureau.

Visit www.ftc.gov for free information on buying, financing, leasing, renting and maintaining vehicles.