How to find out whether a used car has an unrepaired recall

About 5 million used cars under recall were sold last year before the recalled parts were fixed.

A study by Carfax, which sells vehicle history reports, showed overall, there are more than 46 million cars and trucks on U.S. roads with unrepaired safety recalls.

Some of the recalls involve serious safety problems, like leaky brake lines or air bags that can inflate with too much force, sending shrapnel into drivers or passengers.

Others are relatively minor, such as brake master cylinder caps with pictures rather than words.

No matter the problem, if you're shopping for a used car, you want to make sure a recalled part has been repaired. Here's how to protect yourself:

Find whether there's a recall: Get the 17-digit vehicle identification number from the seller, or copy it down from the left side of the dashboard near the windshield. Go to the National Highway Traffic Safety Administration's VIN lookup site at vinrcl.safercar.gov/vin/ and key in the number. The site will tell you if there are any open recalls.

Get a vehicle history report: You can pay a third party such as Carfax or Experian's AutoCheck for a vehicle history check. It will show the car's ownership history, whether it's been in a crash, and whether there are open recalls. Complete reports cost $20 to $40 for a single vehicle at autocheck.com and carfax.com.

Ask the dealer: Many dealers will check used cars for open recalls. Ask them to do it while you're watching. Many have policies of repairing recalls before selling cars, and others will give you a vehicle history report at no charge.

Consider a certified pre-owned vehicle: Manufacturers' certified pre-owned cars often cost more, but all major manufacturers say they check for recalls and fix the cars before selling them.