Key Fob Not Working After a Battery Change? Check These First

When a fob stops working right after a battery change, the usual causes are the wrong battery, a battery in upside down, a bent or dirty contact, or a case that isn’t snapped together. Check those first. If the car still won’t respond, the fob may need attention from a locksmith or dealer.

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Do I Really Need a Locksmith? · Bill’s DIY series

“I can do this myself.” Do I really need a locksmith?

Verdict: You've got this

Watch: change the fob battery first

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Inside: signs your fob is dying, battery swap basics, spare-key tips, what to do if you lose a key, and when to call a pro.

Battery checks

1. Match the battery number exactly. Coin cells look alike but differ in size and thickness. Compare the number on the old battery with the new one.
2. Check the direction. Most coin cells go in with the + side facing a specific way. Look at the marking inside the fob or on the old battery.
3. Use a fresh battery. Batteries can sit on a shelf a long time. Try one from a different pack.
4. Look at the contacts. A metal contact that got bent while you swapped batteries may not touch the battery. Gently check that it presses on the battery.
5. Snap the case fully closed. A case that isn’t seated can leave the battery loose or the buttons not touching.
6. Don’t touch the circuit board with metal tools or wet fingers.

Bill’s video above shows the first step for a Dodge fob. For a step-by-step on Ram trucks, see 2016 Ram key fob not working.

If it still won’t work

• Try the spare fob. If the spare works, the problem is the first fob, not the car.
• Stand closer to the car and try again.
• Check your owner’s manual. Some vehicles have a procedure after a battery change. Most don’t need one, but the manual is the source for your model.
• Check the car battery. A weak car battery can make it seem like the fob isn’t working.

Car won’t start with the fob

Many push-button cars have a backup spot where you hold the fob so the car can read it even if the fob battery is weak. The location depends on the make and model, so check your owner’s manual. Many fobs also hide a mechanical key for the door.

Keep it from happening again

• Write the battery number on a note in your glovebox or phone.
• Swap the battery when the range starts dropping, before it dies completely.
• Keep the spare fob somewhere safe at home, not in the car.
• Open the case with a plastic tool or coin at the seam, not a knife.

When it’s a locksmith job

If neither fob works, a fob was lost, or a fob is cracked or wet, it may need repair, replacement or programming. Automotive locksmiths and dealers handle that. For how locksmiths work on vehicles, see vehicle lockout tools explained.