Peugeot 208 Key Replacement
It is best to delegate the replacement of Peugeot keys for 208 to auto locksmiths who have the equipment and know-how. They can create and program keys more quickly and at a lower cost than a dealership.
A dead battery for your coin is most likely to blame if your key fob stops locking or unlocking doors. There are many other reasons that the key could be malfunctioning.

Dead Coin Battery
A dead coin battery can prevent your Peugeot 208 from locking or unlocking, and won't start the engine. If find out here now is the case, you'll need to make use of the backup starting procedure that is described in the owner's manual of your vehicle.
Another reason why the 208 won't start is because the spark plugs are been worn down. The spark plugs are responsible for sparking the fuel which starts the engine. They have a limited life span. They'll eventually break down if they aren't used frequently enough.
Luckily, there's an easy solution for this problem. Check the voltage of your battery with a multimeter. If it is below 11.5 Volts it is time to replace it. If the battery has corroded it is crucial to clean its contacts. This can be done by removing the rubber cover from the two battery terminals, and then using a wirebrush to clean any corroded parts of the battery. After that, you need to connect the positive pole cables to the negative.
Water Damage
If your 208 doesn't start and the battery has not failed, you should examine the spark plugs. You might find that they are filthy and don't spark. The spark plugs can be cleaned in the workshop.
Peugeot cars use a transponder style key that integrates with the car's immobiliser system. This ensures that only the right key is able to start the engine. If the chip inside the Peugeot key is damaged, then it won't send the correct signal to the vehicle.
Water damage is a frequent cause of this issue. This is a common problem in warmer climates where the vehicle is exposed to snow or rain. In this case, you need to contact an experienced locksmith who has the tools and equipment needed to modify the key. They also have the most up-to-date technology and equipment needed to create the Peugeot 208 smart key. The process should take no more than 15 minutes.
Contacts to the battery are not working properly.
Peugeot replaced the old transponder chips using a new version that makes use of electronic components that are mounted on a circuitboard. The new system is excellent when it's brand new, but the circuit boards deteriorate over time and cease to function properly.
This could stop the immobiliser's function from being activated, meaning your vehicle will not start. If this is the case, it's recommended to contact a Peugeot specialist or locksmith.
A common issue is when the battery inside the key fob starts to die. This causes the blade of the key to stop feeding into your lock. A locksmith for cars will replace the battery and then cut a new key blade for you. This is a quick fix.
Faulty Receiver Module
If your Peugeot key fob stopped working after dropping it on the ground, being exposed to a sudden rain or accidently washing it the wrong way, it could be due a malfunctioning receiver module. The receiver is responsible for transmitting radio frequency signals to the on-board computer that controls the central locking system in your Peugeot vehicle.
Rubber seals on the key fob stop water from getting to the electronic chip. However, prolonged exposure to water may cause damage to these seals and the chip. The high salt content of the ocean or pool could cause damage to the key fob, especially if it is submerged.
The module will have to be replaced if the Peugeot spare key isn't working anymore. This can only be done by a skilled auto locksmith or Peugeot specialist. In contrast to other vehicles, Peugeot keys are protected by an exclusive immobilizer system that requires the correct coding to start the engine. This is the reason why you should only trust an experienced Peugeot locksmith to handle the task of programming and creating the replacement.
Computer with a problem on board
The on-board computer in your Peugeot is responsible for a variety of the systems within your car, ranging from power windows to the airbags. The on-board computer displays a code when something goes wrong. This code is saved in the system and stays there until the issue is solved. This could mean that the on-board computers to be replaced.
One of the most common causes of the light turning on is the loose or corroded connections in the airbag sensor. This can be caused by wear and tear, ageing, or exposure to moisture and salt. This issue should be addressed as soon as you can, as an airbag that is malfunctioning could be dangerous in the event of an accident.
If your Peugeot is showing a card that is not being detected error then the key battery inside the key fob could be weak or dead. This prevents the key fob from sending a signal to disable your vehicle's standard immobilizer. You can test this by pressing the unlock button on the key fob and then attempting to start your car. If this does not work then the battery in the key needs to be replaced.