Reasons Your Fiat 500 Key Fob Won't Work A Fiat 500 key fob makes it easy to open doors and start your car. However, there are a variety of reasons why the key fob might stop functioning. This could be due to a dead coin battery damaged receiver module, water damage issues, and interfering. 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 find local automotive locksmiths). Includes trunk, lock and unlock buttons. Dead Coin Battery The most frequent reason why your 500 key fob will not function is an inactive battery. Modern key fobs have only a limited range of operation and must be within a few inches of your vehicle to work. If you're not close to your vehicle when you press the key fob button the car won't respond, and will display an "Key Fob Not Detected" message in the instrument cluster. If this happens, replace the battery of your coin cell (Part number CR2032) with a new one from a reputable manufacturer like Panasonic, Duracell, or Energizer. You can find them in your local hardware store or on the internet. After you've replaced the battery in the coin cell you can test it by standing near your Fiat 500 and pressing the buttons. The parking lights will flash and the key fob should operate the lock and unlock switches. If the key fob doesn't work after replacing the battery, it may be damaged by water that blocks it from communicating with the receiver module inside your vehicle. Water damage can happen through a variety of methods, including simply splashing or submerging the key fob in saltwater at the beach. If you believe your fob was exposed to water, put it in a rice bag to draw out the moisture. If that doesn't work, your fob will probably need to be reset by an experienced auto locksmith or by the dealer. Water Damage Water damage can happen if you immerse the fob into the ocean or wash it in a machine. Saltwater can cause the circuit board to short and eventually die. If you get the fob wet, it's not an option but if you drop it in a cup of water or don't remember to remove it from your pants pocket prior to running the washing machine Don't give up hope. First take the battery off the fob. Before replacing the battery clean the electronic chip using isopropyl, or a similar product. Then try the fob and test if it works. If the key doesn't function it could need to be reprogrammed. This is usually done by an auto locksmith or dealer. If the key is a newer model and hasn't been programmed to your vehicle, it will likely need to be replaced completely. A professional locksmith in the automotive industry will be able to complete this process. The locksmith will need to cut the key to match the ignition in your vehicle. They will also need to program the fob into the system of your car. This is an affordable and quick process that can be completed the same day. Receiver Module Issues The 500 key fob could not function because it's out of range. The remote typically has an area of 30 feet or less and if it's far from your vehicle, it will not respond to your commands. This can be easily fixed by moving closer to your vehicle until it starts responding. If you've replaced the coin battery (commonly known as"button" or "button" or "watch") and the fob isn't working it could be due to an internal circuit board problem. Reprogramming the fob usually resolves this problem. You can find the steps for most vehicles on YouTube or in the owner's guide. It could be necessary to replace the metal clips that hold the coin batteries in place. If they lose tension they could stop the coin battery from being properly seated and could cause your remote to malfunction. In rare instances it is possible that the fob will become desync'd with your vehicle due to software issues or hardware issues. This issue can be fixed by visiting your local auto-locksmith or dealer to reprogram your key fob. In some cases they might need to reinstall the program in your body control module as well. Interference Interference can also cause the key fob to not receive or transmit an signal. This could occur if the key fob is near radio transmitters (cell phones and radar detectors) or another source of electromagnetic radiation. Other reasons the key fob could not function include a weak connection to the buttons or damage to the internal chip, or water damage. If the key fob been unable to function for a while in the middle of the night or after trying every option at home to fix it e.g. replacing the battery, reprogramming, and using the spare key fob, you might have a malfunctioning receiver module on your 500. The receiver module, located under the dashboard, detects radio frequency signals from your key fob. It transforms the signals into electronic commands that are then translated by the vehicle. There's a quick and easy way to reset the 500's in-board system including the keyfob. Disconnect https://www.thekeylab.co.uk/fiat-car-keys/ for 15 minutes by removing first the negative cable and then the positive cable. Then, reconnect the battery. This will eliminate any residual electricity and restart the car's computers, which could help the key fob to function again. If the issue continues, you should seek out an expert technician. They will be able to identify the root cause of your issues.