Reasons Your Fiat 500 Key Fob Won't Work A fiat 500 key fob is a convenient method to unlock the doors and start the car. There are many reasons the fob may stop working. These include a dead battery damage to the receiver module, water issues, and interference. This listing is for an NEW replacement Fiat Flip Key Remote that appears similar to the Ilco brand. It must be professionally programmed (click here to search for local locksmiths for your vehicle). https://www.thekeylab.co.uk/fiat-car-keys/ comes with lock, unlock and trunk buttons. Dead Coin Battery A dead battery is the most frequent reason for your 500 key fob that isn't working. Modern key fobs offer an operating range that is limited and must be within only a few inches from the vehicle to work. If you're far away from your vehicle when you press the key fob button, the car won't be able to respond, and will display an "Key Fob Not Detected" message in the instrument cluster. If this happens, simply replace the battery in the coin cell (Part number CR2032) with a brand new one from a trusted brand such as Panasonic, Duracell, or Energizer. They are available at your local hardware store or on the internet. After you've replaced the battery of your coin cell you can test it by standing in front of your Fiat 500 and pressing the buttons. The parking lights should light up and the key fob will operate the lock and unlock switch. If your key fob isn't working even after replacing the battery, there may be water damage which prevents it from interacting with the module inside your vehicle. Water damage can happen in many ways, including an easy splash or submerging the key fob in saltwater at the beach. If you suspect that your fob was exposed to water, place it in a bag of rice to draw out the moisture. If this doesn't work your fob may need to be reprogrammed by a professional auto locksmith or dealer. Water Damage The fob does have rubber seals to keep water out of the electronic chip inside, submerging it in the ocean or washing it in a machine can cause water damage. Saltwater can cause the circuit board to short, and eventually fail. Getting the fob wet is not an ideal choice but if you accidentally drop it in the water in a cup or fail to remove it from your pocket before you run the washing machine, don't give up hope. First remove the battery from the fob. Before replacing the battery, clean the electronic chip with isopropyl or another similar product. Check the fob again to verify if it's working. If the fob doesn't work, it might need to be changed. This is usually done by an auto locksmith or dealer. If the key is older and has not been programmed to your vehicle it is likely to need to be replaced completely. A professional locksmith for automotive can carry out this simple task. The locksmith will require the key cut to match your car's ignition. The locksmith also needs to reprogram your fob in the vehicle's system. This is a cheap and quick process that could be completed on the same day. Receiver Module Issues The 500 key fob could stop working because it is out of range. The remote usually has an operating range of 30 feet or less, and if it's too far from your car, it won't respond to your commands. This can easily be resolved by moving it closer to your vehicle until it starts responding. If you've replaced the coin battery (commonly known as a "button" or "watch") and the fob won't work it could be due to an internal circuit board problem. Reprogramming the fob usually resolves this issue. You can find the procedure for most vehicles on YouTube or in the owner's manual. You may have to replace the metal clips that keep the coin battery in place. If they loose tension, it could prevent the battery from being seated properly, and this will result in the malfunction of your remote. In rare cases the fob might become desync'd with your vehicle due to software or hardware issues. This can cause a major headache, but you can usually resolve this issue by visiting an auto locksmith to reprogram your fob for you. In certain instances the software might require reinstallation to your body control modules. Interference In addition to a dead battery on a coin The key fob may not be able to transmit or receive signals due to interference. This could happen when the keyfob is in close proximity to a radio transmitter, like a cellphone or radar detector. The key fob may not function because of a weak connection with the buttons water damage or damage to the internal chips. If your key fob suddenly stopped working, or you've tried everything at home to resolve it (e.g. replacing the battery, reprogramming, and using the spare key fob, you could have a malfunctioning receiver module on your 500. The receiver module, which is located under the dashboard, picks up radio frequency signals from your key fob. It converts the signals into electronic commands which are then interpreted by the vehicle. Fortunately, there's an easy way to reset all on-board systems in your 500 device, including the key fob. Disconnect the battery of 12 volts for approximately 15 minutes by removing the negative cable first then the positive cable. Then reconnect the battery. This will erase any remaining electrical charge, and then restart the computer of your car. This will help you get your key fob to function again. If the issue persists it is recommended that you consult an expert certified technician. They will be able to determine the exact cause of your problems.