AutoTrader Answers: What to Do If Your Car’s Key Fob Battery Dies

Have you ever approached your vehicle only to discover your key fob won't unlock it? Before you panic, read this article and watch this video to find out how to get into your locked vehicle and start it, as well as how to replace the battery in your fob easily.

Step 1: Find the redundant key in your fob

Almost all modern key fobs have a simple key hidden inside them and removing it entails finding a latch and pulling the slide (that is, the section of the key with ridges and textures) out of the fob.

Step 2: Find the lock cylinder on the outside of your car

A lock cylinder, the part you slide the key into, is sometimes easy to see on or under a door handle. Unfortunately, it can sometimes be hard to find, too, and may be hidden behind a door handle. Once you’ve located it, insert your key and twist to unlock your vehicle.

Step 3: Start your vehicle

Even if your key fob is too dead to unlock your vehicle, it should still be able to start it. Simply place the fob close to a contact patch that might be on the steering column, the centre console, or within the start button. With your key against the patch, you should be able to start your vehicle by pressing the start button.

Step 4: Find your fob’s battery

If your fob has an apparent fastener, such as a screw, remove it. If not, use a screw driver or other tool to pry your fob open and expose the battery — if you’re unsure how to open your fob, try looking in your owner’s manual or Googling your model of vehicle and “replace battery” for more specific instructions.

Step 5: Replace your fob’s battery

Now that the key fob is open, pull the battery out, and try to identify the type. Normally, this is plainly written on the battery. Buy yourself a new version of the same battery, put it in your fob in the same orientation as the old one, close it all back up, and you should be good to go.