Start with the battery
A weak battery is the most common reason a key fob stops working. South Florida heat and humidity can drain it sooner. Signs include having to stand closer to the car, pressing a button several times, or a "key battery low" message on the dash. Most fobs use a coin battery you can change at home: the battery type is printed on the old one, and the owner's manual shows how to open the case.
Put the new battery in the same way the old one came out and press each button. If the remote works again, you are done. If it still does nothing, or works only some of the time, go through the next checks before you buy anything new.
Try your other fob and look around you
If you have a second fob, try it. When the spare works and the first one doesn't, the problem is in that fob: the battery, a worn button, water or salt-air damage or a broken board. When neither fob works, the problem is more likely on the car's side, such as a weak car battery or a fault in the receiver or the module that listens for the remote.
Strong radio signals can also block a remote for a while. Parking garages, areas near radio towers or airports, and some chargers and electronics can cause it. Try again from a different spot. Keep a smart key away from phones and other fobs in the same pocket or bag.
When a fob needs programming
Some situations always need programming, not just a battery. A brand-new or used fob bought online has to be programmed to your car before it does anything. On some older cars a remote loses sync after a battery change, and a fob or module replaced after a repair has to be matched to the car again. That is when a key fob replacement or reprogramming makes sense.
Before you buy a fob online, text us a photo of it and of its part number. Some used fobs are locked to the first car they were programmed to and can never work on another one, and some look right but have the wrong frequency or chip for your car.
Smart keys: what "key not detected" means
On a push-to-start car, a "key not detected" message means the car can't hear the smart key inside the cabin. The usual cause is a weak fob battery, but phones, laptops and other fobs close by can also get in the way. A fob that was dropped or got wet may still unlock the doors and then fail once you are inside the car.
Most push-to-start cars have a backup way to start with a weak fob, built in by the maker: usually you hold the fob close to the start button or set it in a marked spot. Your owner's manual shows where it is on your car. If the message keeps coming back with a fresh battery, the key or the car's antenna needs to be checked.
When it's time to call a locksmith
Call a locksmith when a new battery and the spare fob don't solve it, when you bought a fob that needs programming, or when you are down to your last working key. We come to the car anywhere in Miami-Dade or Broward, check the fob and the car, and program a new or replacement fob on site when the car allows it. If your car needs the dealer, we tell you honestly.
- New battery, still no response
- Spare fob works, main fob doesn't
- "Key not detected" keeps coming back
- A fob bought online needs programming
- Only one working key left
