How to Check a Key Fob to See if It Is Working

by Susanne Koenig
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Today's keyless remotes -- also known as key fobs -- make life easier. No more balancing your groceries on the bumper fumbling with car keys or making sure every door lock is down. It can be particularly frustrating when your key fob stops working or starts to perform sporadically. Check your key fob to make sure it is in top condition so it will work when you really need it.

Step 1

Take your key fob out to your car. Press the alarm button. If the car horn fails to engage, your key fob is not sending the proper signal. The fob must send a signal that is strong enough for the car to respond.

Step 2

Change the battery. All key fobs require a standard watch battery. You can have it changed at a jewelry store or change it yourself with a small Philips or flathead screwdriver. If there is a screw in the back of the fob, remove it, and pry the fob apart to reveal the battery. Replace the battery with the positive side up and snap back closed.

Step 3

Reset your fob if the battery is new and it still is not working. Since fobs work on a radio frequency, they often will be disrupted by another electronic emitter such as a electronic toll-booth scanner or an electronic payment device that is attached to your key ring. Instructions for resetting your fob will be included in the cars owner manual. Use the car's "programming" mode to reset your fob.

Step 4

Visit a dealership or an automotive locksmith if your key fob still does not respond, especially if it is under warranty. A reputable automotive locksmith will cost less if you have to replace the key fob. A key fob's buttons will wear out the electrical contacts with use. These can be repaired at home with an application of conductivity paint (sold at electronics stores) but only do so if you are used to working with electronics.

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