fiat 500 keys contain an transponder chip that transmits the signal to your vehicle to unlock the doors or start the engine. However, the fob may stop working for several reasons.
The most frequent cause of key fob malfunction is the battery of the coin is dead. Other causes are water damage or a malfunctioning module and interference signals.
Dead Coin Battery
If your key fob's battery has failed, the initial step is to replace it. Make use of a new button battery that has the same size, voltage and specifications like the previous one.
If the key fob has been exposed to water, for example a splash of rain or salt water on the beach, it needs to be cleaned before it is able to be used again. The best method is to use a paper towel that has been soaked in isopropyl or electronic cleaner.
If the key fob isn't working even though it is not exposed to water it could be due to a glitch in the receiver module or internal electronic chip. In these situations it is possible to re-programme the key fob with an OBDII scanner could aid.
Water Damage
It is possible to get water damage to your key fob if it was submerged in a puddle, pool or washing machine. It is usually possible to get it working again by taking off the battery and then scrubbing the circuit board with isopropyl alcohol. It is best to let the fob completely dry prior to installing a battery.
You may have a faulty module in the event that your remote stops working after replacing the battery or updating. You can find instructions for reprogramming most vehicles' remote keys on YouTube, or consult your owner's manual. You could also try resetting the car's onboard computer by using the OBDII scan tool.
Faulty Receiver Module
The key fob has the chip that communicates the vehicle's system. If this chip becomes damaged, it will no longer send and receive signals to the vehicle. The key fob being dropped can result in this, as can exposure to water. If your key fob has stopped working due to exposure to water, you may be able fix the issue if you clean the chip using electronic cleaner or isopropyl alcohol.
If the key fob does not respond to cleaning, it is possible that the receiver module has a fault and needs to be replaced. A malfunctioning receiver could cause the key to stop working. This is usually caused by electromagnetic interference.
Faulty Electronic Chip
The chip that is embedded in the key fob is an essential component of the anti-theft systems in your car. It transmits a signal to the immobiliser unit in the vehicle to determine whether or not the key is legitimate. If the chip is damaged or broken, your vehicle will not start.
A malfunctioning chip could be caused by interference signals from other objects like bad weather conditions or transmitters on the same frequency as your vehicle. In this situation you'll need an entirely new key fob.
Faulty battery contacts
The battery contacts in a key fob are very delicate and may be damaged when used for long periods of time. If they're bent or damaged, the fob will not send any signals to receiver modules inside the vehicle.
Modern fobs are equipped with rubber seals to keep out water. Submerging them in water, even if it's only the slightest splash or drizzle could harm the chip's electronic components.
The key fob comes with chip that communicates with the immobilizer system of the vehicle to start it. This system utilizes cryptocoding systems in newer vehicles as well as the traditional red key system for older ones. If the chip is defective it will have to be replaced.
The 12 Volt Battery is faulty
A faulty battery can cause the key fob to cease working. The car's computer will not recognize the remote when this occurs.
Test the battery using the voltmeter before replacing it to determine its capacity. A fully charged battery should display 12.6 volts. If the reading drops dramatically it's time to change it.
To test the battery's power to determine its capacity, put an electric load on it for a few minutes. This will remove approximately 1 percent of the charge on the surface. After that, take the voltage again. The greater the battery's capacity is, the longer it will keep its voltage. Ideal is to hold close to 12 volts during several minutes.
Faulty Radio Signal
This is the most frequent reason for the key fob to stop sending signals to a car. This issue can be fixed by replacing the battery. It is however important to choose a battery that is the same size and voltage as the original one.
Fobs aren't impervious to damage and can take a lot. Contacts and buttons on batteries can be damaged through rough handling.
Other objects or transmitters using the same frequency can disrupt the signal. For instance, a lighting control panel close to your home can transmit interference on the same bandwidth that key fobs use. This could affect the remote control of your car.
Problems with OBDII Scan Tool
There are a variety of reasons why a scanner tool may not perform. Some are more complicated than others.
Professional scan tools enable mechanics to examine the car's systems and perform a variety of self-tests. These tools can save a lot of time, but are costly and not accessible to the majority of DIYers.
If your OBD2 scanner won't turn on Check the voltage on terminal 16 (scan tool power) and terminal 4 (chassis ground). If both are in good condition the fuse could have blown. This is among the most common causes of a scan tool failing. It is generally easy to fix the problem by replacing the fuse blowing up.