Seat Leon Key Fob Replacement
It's not always required to replace or reprogramme your seat remote fob, if it has stopped working. First, you should check the battery. Most fobs have a slider, switch or small gap you can use to remove and replace the battery. Make sure you use the same type of battery as the original.
Dead coin battery
One of the most common causes of a key fob that stops working is a dead battery. Replacing it is easy and takes just some minutes, but the first thing to be sure to make sure you're using a suitable type of battery. The majority of key fobs use CR2032 3V batteries, available in a variety of electronics stores and online. There are instructions on how to open the key fob and replace its battery in your owner's manual, YouTube video, or other online resources.
Water Damage
Even if your Leon key fob is water-proof, prolonged exposure to salt water could affect the internal electronic chip that controls the remote. In some cases this can also stop the key fob from communicating with your vehicle. You'll need to clean the battery with isopropyl or an electronic cleaner, and dry it prior to placing the battery back.
If the battery isn't the problem, it could be that the buttons are stuck or misaligned due to a lot of use. A thorough visual inspection will identify if they're loose or damaged and can be repaired by soldering them back into place. You could do it yourself, or you can take the key fob to an auto shop for repair. It may be necessary to replace the remote, based on the level of damage.
Faulty battery contacts
A damaged or defective battery contact is one of the most common causes for the keyfob to stop working. This could be due to dirt or water inside the case of the key fob or wear and tear over time. Isopropyl Alkohol can be used to clean the battery's contacts. This will restore communication between the microprocessor, the battery, and the key fob.
The battery can be replaced within your Leon keyfob by prying the two halves apart with a flat screwdriver. A new battery is cheap and can be purchased at any electronics retailer. Be sure to follow the directions in your owner's manual when taking off and installing the new battery.
You can also try resetting your remote keyless system by disconnection of the 12 volt battery for a short period of time. This will reset all the on-board computers and may bring back the ability of your key fob to connect to the vehicle. If the issue persists, you should contact a dealer to reprogram the key. They will employ an OBDII scanner in order to determine the problem and may be able to reprogram your key fob, without the need for another original key. This process is usually completed in less than one hour. The dealer will also be able to reset the immobilizer.
Water damage
It's essential to act promptly if your key fob has been soaked by water. Water and electronics aren't an ideal combination and could cause damage to the circuit board. A key fob that's wet is also likely to not function properly, which is why it's important to fix this issue as quickly as you can.
If you accidentally dropped your keyfob into water or a pool, or washed it accidentally then you must take it off first and let it dry completely. You can also use a paper towel or tissue to dry the casing. You can also put it in a bag that is filled with silica gel bags to aid in the absorption of the moisture.
When your key fob is completely dry, it's time to start putting it back together. Make sure the battery is properly inserted and the contacts made of metal on the circuit board are clean. If you need to, use a little isopropyl clean the contacts.
It should be possible to start your car with the fob of your key after all this. However, if it still doesn't start your vehicle there may be additional problems that need to be taken care of. It could be a malfunctioning key or transponder that needs to be reprogrammed.
The receiver module is not working properly.
If your key fob isn't functioning after dropping it on the floor or simply was not working out of black and you've tried every other option including replacing the battery, reprogramming it, and using a spare key fob it could be time to replace the receiver module. This electronic component sends signals to the other modules in the car, like the immobilizer. Without a working receiver module, the security system of your car won't function and you won't be able start your vehicle.
If TheKeyLab inside your seat leon is damaged or isn't sending the correct radio frequency signals, you'll notice an error code on the instrument panel. In many cases, the issue can be solved by connecting an OBDII scanner to the vehicle's diagnostic port and examining it for issues. Then you can try reprogramming the key with a dealer-provided programmer to see if this resolves your problem.
Key fobs are exposed to many abuses, which is why they're not impervious to destruction. The battery terminal contacts as well as the button are the most frequently encountered failure points. With a little effort, you can easily repair or replace these. Check the voltage on your car's key fobs with an voltmeter to determine if they're low. If the battery's reading is lower than 3 Volts the time is now to replace it. You can find an alternative battery from any auto part or electronics center.