Fiat 500 Key Fob Replacement
If your 500 keyfob stops working, try a different one to see if it can be detected by your car. If it does, the issue is most likely due to the original fob's battery, or water damage.
First replace the battery. The "+" side should be facing down.
Dead Battery
The battery is often the reason for the fob not functioning. It's easy to fix, and most fobs provide a warning signal if the battery is running low. There are instructions on YouTube for nearly every car's key fob or look in the owner's manual. You can also replace it by taking it to an authorized locksmith or a dealer who supplied it to you.
Sometimes, a fob may cease to function, and it could be a problem with the internal circuit board. It is rare but it does happen. The internal chip can be damaged in the event you drop the fob on something hard. This could also happen if you use an aftermarket key and the fob does not work. In this case you'll have to visit a locksmith or dealer and have it reprogRammed to work with your 500.

One 2012 FIAT 500 Flip Key Remote - resembles Ilco brand with lock, unlock and trunk buttons. New replacement keyless entry remote (will require cutting and programmed by a locksmith)
Damaged Chip
Fiat 500 key fobs are wireless devices that transmit signals to the car when you press the button. It has a microchip which contains the code that will allow it to communicate with the car. If the chip is damaged, it can't transmit the correct code and the car won't start. Locksmiths can repair this type of damage. United Locksmith can complete this service on both classic and modern models, so do not hesitate to contact us.
You can purchase a brand new fob and have it programmed professionally by locksmiths. This is much cheaper than visiting a dealer, and it will work exactly the same way. You'll need certain information to the locksmith, such as the year that your car was manufactured and the model.
If you are not sure how to solve this problem try rub the chip with the help of a US dollar bill. The copper on the bill is abrasive enough get rid of dirt and oxidation but it will not cause any damage to the microchip. The chip might not be repaired in the event of physical damage. fiat 500 key button replacement can happen when you drop it, run it over by accident with your vehicle or experience any other kind of physical trauma.
Water Damage
Water damage is likely to happen on your fob, no matter if you dropped them in the pool unintentionally or put them in pockets while swimming, or splashed water on them during a rainy afternoon. Even if there's only some water on the keys, this could cause serious problems to its electronics and stop it from working properly.
The good news is that you can usually solve this issue by removing the fob's key and using a paper towels to rid it of any dirt or water that remains. After the fob is dry it is possible to replace its battery. It should then start working again.
You can take it to an auto repair shop or locksmith to get it professionally cleaned and programmed. These professionals will be able to use special equipment to make sure that the key fob works with the car's computer system.
When your Fiat 500's key fob isn't working, it can be frustrating and stressful. It can be costly and time-consuming to take your key fob to a dealer. Locksmiths can replace your key fob with no need to visit the dealership. Locksmiths are better than a dealer, as they can handle every aspect of the replacement of your car's key fob without the requirement for a dealership visit.
Pairing Issues
If you accidentally drop your keyfob or it ceases to function and nothing else seems to be wrong, it may be the chip. It could be due to water damage or a dead battery. it may be due to a need to reprogramme.
In most cases, this can be done by following the instructions in your owner's manual. If you are having trouble or your manual doesn't work it is recommended that you have an automotive locksmith take care of this task. This will ensure that the chip is not fried, and it's also the most affordable alternative.
A few hundred owners have reported that their keys will not lock their cars. This can be a problem if you need to refill at gas stations. Some owners have even reported their 500's locking mechanism failing and requiring replacement of the entire intermediate shaft of the steering. Fiat has actually cited this problem in an technical bulletin (TSB).
A reputable locksmith will assist you should your Fiat is having problems. They can duplicate the key you have or make you a brand new key that locks and starts the vehicle. They can do this without having access to your old key, and it's generally cheaper than purchasing one from a dealer.